Me, myself & IT

Stop Malware with Software Restriction Policies alias SAFER

Purpose

Reason

Impact

Operation

Advanced Logging

Availability and Vulnerability

Reliability and Safety

Interoperability and Security

Prerequisites

Loopholes, Limitations, Dependencies and Bugs

Details

Background Information

Fallacies, Misconceptions and Myths

Implementation and Build Details

Authenticity and Integrity

Download

Installation

Automatic online installation

Manual offline installation

Test

Update

Upgrade

Deinstallation

Bugs

Purpose

Note: the setup script NTX_SAFER.INF removes overwrites the bogus AppLocker registry entry which disables SAFER on Windows 11 22H2!

This technique is known as Application Whitelisting; the setup scripts presented here perform a rather permissive implementation: they allow execution of all applications which are properly installed by an administrator.

Note: the MSDN article Security Considerations: Microsoft Windows Shell provides details for proper installation!

Reason

Note: the SAFER ruleset takes care of NTFS Alternate Data Streams too!

Unlike unreliable, unsafe and vulnerable antivirus software which almost always fails to detect new or unknown malware (ransomware, trojan horses, viruses, worms, …), known as false negative, or misdetect legitimate clean software as malware, known as false positive, this method effectively stops all kinds of known as well as new or unknown malware and all other unwanted or unauthorised software that uses executable files to infest Windows NT installations, while allowing all legitimate software to run, without introducing new vulnerabilities or weaknesses!

The TechNet article Security Content Overview states in the section Client Hardening:

Software restriction policies are a key security feature of Windows XP that can be used to lower the risk of users installing or running unauthorized software, including potentially dangerous viruses or other types of malicious software. Microsoft also recommends that organizations give their users the minimum privileges that they need to perform their job functions. Users with administrative rights may be able to bypass many of the security countermeasures you put in place.

Impact

• are still able to download arbitrary (executable) files from arbitrary web sites, to receive arbitrary (executable) files as attachments of mails, etc. and store them anywhere they are allowed to write files, but they can’t execute these files any more;
• can execute all Win32 applications that meet the minimum requirements of the more than 25 year old Designed for Windows specification, i.e. have their executable files installed beneath the directories %ProgramFiles%\ or %SystemRoot%\;
• can’t execute applications installed in their User Profiles, stored on external, portable or removable devices and media, or on other computers;
• can open all files with any application installed on their machines by their administrators, i.e. they can work with all their documents and all local applications without any restriction.

Warning: some imbeciles who don’t recognise the simple word data in the directory pathnames %ProgramData%\ alias %SystemDrive%\ProgramData\, typically C:\ProgramData\, %APPDATA%\ alias %USERPROFILE%\AppData\Roaming\ alias %SystemDrive%\Users\‹username›\AppData\Roaming\, typically C:\Users\‹username›\AppData\Roaming\, or %LOCALAPPDATA%\ alias %USERPROFILE%\AppData\Local\ alias %SystemDrive%\Users\‹username›\AppData\Local\, typically C:\Users\‹username›\AppData\Local\, and are unable to realise its meaning, install or place but executable files below these directories!
For a recent demonstration of such gross incompetence see the MSKB article 4052623.
For current and previous offenses see for example the Teams Desktop App shipped and installed with Windows 11, the OneDrive Client shipped and installed with Windows 10, Mozilla Firefox, Mozilla Thunderbird, Google Chrome, Google Drive, ….

Caveat: the setup scripts NT6_SAFER.INF and NTX_SAFER.INF deny execution for unprivileged users underneath the directory %SystemRoot%\System32\DriverStore\, where imbeciles from AMD^®, Intel^® and nVidia^® unfortunately install their (graphic) drivers lately, subverting the DriverStore, introduced with Windows Vista as repository for drivers and used as staging area during their installation; one of its intended purposes is to enable the easy repair of installed drivers in case of corruption.

If you want to use such braindead setup drivers, add a path rule to allow execution in their staging directory %SystemRoot%\System32\DriverStore\FileRepository\‹filename›.inf_‹architecture›_‹MD5 hash›\.

Note: exemption of privileged users from Software Restriction Policies leaves no loophole!
Privileged users can write files in the directories where execution is allowed, can disable or remove Software Restriction Policies and can thus execute any file.

If you want or need to restrict administrators too, use the setup scripts NT6_SUPER.INF (for all editions of Windows Vista, Windows Server 2008, Windows 7 and Windows Server 2008 R2) or XP_SUPER.INF (for all editions of Windows XP, Windows Server 2003 and Windows Server 2003 R2).

Caveat: on Windows 7 and newer versions of Windows NT, all SAFER security levels except Unrestricted alias Fully trusted are equivalent to Disallowed and deny execution!

Determine Your Application Control Objectives:

SRP on Windows Vista and earlier supported multiple security levels. On Windows 7 that list was restricted to just two levels: Disallowed and Unrestricted (Basic User translates to Disallowed).

Note: user accounts created during Windows Setup are but privileged user administrator accounts!
Change their account type to Standard User (on Windows Vista and newer versions of Windows NT) or Limited User (on Windows XP, Windows Server 2003 and Windows Server 2003 R2) respectively if you use them for your routine work!

Change a user’s account type:

When you set up Windows, you were required to create a user account. This account is an administrator account that allows you to set up your computer and install any programs that you'd like to use. Once you finish setting up your computer, we recommend that you create a standard account and use it for your everyday computing. If you create new user accounts, you should also make them standard accounts. Using standard accounts will help keep your computer more secure.

Note: the dumb User Accounts control panel applet denies to demote the last or only privileged user account even if the builtin (real) Administrator account is activated!
Use the real User Accounts control panel applet instead: to start it, run one of the equivalent command lines

Control.exe UserPasswords2
NetPlWiz.exe
RunDLL32.exe NetPlWiz.dll,UsersRunDll

If you prefer the command prompt over the graphical user interface, run the following command lines with administrative privileges and access rights:

Net.exe LOCALGROUP Administrators "%USERNAME%" /Delete
Net.exe LOCALGROUP Users "%USERNAME%" /Add

Caveat: don’t forget to enable the builtin Administrator account; run the command line

Net.exe USER Administrator /Active:Yes /PasswordReq:Yes

Caveat: don’t forget to set a (strong) password for the builtin Administrator account!

Caveat: Windows 10 has the nasty habit to disable the builtin Administrator account during updates and upgrades!

Note: the (predefined) privileged user account NT AUTHORITY\SYSTEM alias LocalSystem is always exempt from Software Restriction Policies; the (predefined) unprivileged user accounts NT AUTHORITY\LOCAL SERVICE alias LocalService and NT AUTHORITY\NETWORK SERVICE alias NetworkService are but subject to them!

Operation

Note: the Win32 functions LoadLibrary(), LoadLibraryEx(), LoadPackagedLibrary(), ShellExecute() and ShellExecuteEx() yield error code 5 alias ERROR_ACCESS_DENIED instead.

For (portable) executable files except DLLs, one of the messages shown above is displayed and an entry 865, 866, 867, 868 or 882 from source Software Restriction Policies (on Windows XP, Windows Server 2003 and Windows Server 2003 R2) or Microsoft-Windows-SoftwareRestrictionPolicies (on Windows Vista and newer versions of Windows NT) is written to the Event Log.
For Windows Installer packages, patches and transformations, one of the messages shown above is displayed and an entry 1007 or 1008 from source MsiInstaller is written to the Event Log.

To retrieve these entries from the Event Log, start the Command Processor and run (one or more of) the following command lines:

WMIC.exe NTEvent Where "EventCode='865' Or EventCode='866' Or EventCode='867' Or EventCode='868' Or EventCode='882'" Get /Value
WMIC.exe NTEvent Where "SourceName='Software Restriction Policies'" Get /Value
WMIC.exe NTEvent Where "SourceName='Microsoft-Windows-SoftwareRestrictionPolicies'" Get /Value
WMIC.exe NTEvent Where "(EventCode='1007' Or EventCode='1008') And SourceName='MsiInstaller'" Get /Value

Advanced Logging

The NTFS DACL of the directories %SystemRoot%\Debug\ and %SystemRoot%\System32\LogFiles\ allow only privileged users (NT AUTHORITY\SYSTEM alias LocalSystem and members of the BUILTIN\Administrators group) to create the file %SystemRoot%\Debug\SAFER.log or %SystemRoot%\System32\LogFiles\SAFER.log respectively.
The file’s inherited access permissions also allow only privileged users to write, but unprivileged users (members of the BUILTIN\Users group) to read.

On Windows Vista and newer versions of Windows NT, file and directory operations of 32-bit applications run by unprivileged users which fail due to missing write access permissions in %SystemRoot%\ and below as well as %ProgramFiles%\ and below, on 64-bit editions also %ProgramFiles(x86)%\ and below, are redirected to the directory %LOCALAPPDATA%\VirtualStore\, resulting in %LOCALAPPDATA%\VirtualStore\Windows\System32\LogFiles\SAFER.log.

Caveat: the file SAFER.log can grow quite large!
Note: it can be cleared or erased any time.

Availability and Vulnerability

Note: their successor AppLocker is available on Ultimate and Enterprise editions of Windows 7 and newer versions of Windows NT only, while Device Guard is available only on Enterprise editions of Windows 10 and Windows 11.

Unlike antivirus or other so-called security software which is often typically vulnerable itself, Software Restriction Policies introduce no additional code which allows to leverage successful attacks in the first place!

Some, but not all (now fixed) vulnerabilities in Microsoft^®’s anti-malware products for consumers are documented in the MSKB articles 932135, 952044, 2823482, 2847927 and 3074162, the Security Advisories 2491888, 2846338, 2974294, 3074162 and 4022344, plus the Security Bulletins MS07-010, MS08-029, MS13-034 and MS13-058.

The additional updates to harden the anti-malware products for consumers are documented in the MSKB articles 2781197, 2856373, 2883200, 2894853, 2939153, 2976536 and 3025417.

Note: so-called security products of other vendors are equally bad or even worse!

Analysis and Exploitation of an ESET Vulnerability:

Do we understand the risk vs. benefit trade-offs of security software?
Tavis Ormandy, June 2015
[…]
Attackers can cause I/O via Web Browsers, Email, IM, file sharing, network storage, USB, or hundreds of other vectors. Whenever a message, file, image or other data is received, it’s likely some untrusted data passes through the disk. Because it’s so easy for attackers to trigger emulation of untrusted code, it’s critically important that the emulator is robust and isolated.

Unfortunately, analysis of ESET emulation reveals that is not the case and it can be trivially compromised.

Because antivirus products typically intercept filesystem and network traffic, simply visiting a website or receiving an email is sufficient for exploitation. It is not necessary to open or read the email, as the filesystem I/O from receiving the email is sufficient to trigger the exploitable condition.
[…]
Product Design Flaws

I've also reported some major design flaws in various other components of Kaspersky Antivirus and Kaspersky Internet Security. The patches for the remote network attacks I had planned to discuss here were delayed, and so I'll talk about them in a second post on this topic once the fixes are live.

Security Software Considered Harmful?

We have strong evidence that an active black market trade in antivirus exploits exists. Research shows that it’s an easily accessible attack surface that dramatically increases exposure to targeted attacks.

Today we're publishing details of multiple critical vulnerabilities that we discovered, including many wormable remote code execution flaws.

These vulnerabilities are as bad as it gets. They don’t require any user interaction, they affect the default configuration, and the software runs at the highest privilege levels possible. In certain cases on Windows, vulnerable code is even loaded into the kernel, resulting in remote kernel memory corruption.

Reliability and Safety

On the right, the screen shot of a message box shows antivirus software which is disabled by malware (ab)using Software Restriction Policies, i.e. this antivirus software was even unable to protect itself!

Note: Self-Protection for Antivirus Software provides an overview!

Trend Micro: Antivirus industry lied for 20 years:

In the antivirus business, we have been lying to customers for 20 years. People thought that virus protection protected them, but we can never block all viruses. Antivirus refresh used to be every 24 hours. People would usually get infected in that time and the industry would clean them up with a new pattern file.
In the last 20 years, we have been misrepresenting ourselves. No-one is able to detect five and a half million viruses. Nowadays there are no mass virus outbreaks; [malware] is targeted. But, if there are no virus samples submitted, there’s no way to detect them.

The best kind of desktop is a secure desktop. As you all know, hackers are a tricky bunch. You have to go beyond Symantec Antivirus and actually lock Windows down if you want to make sure your computing environment is actually secure.

For example, application whitelisting on end-user devices stops advanced and zero day attacks from infecting the system by preventing unauthorised code execution, protecting memory, and blocking attempts to exploit a whitelisted app before it gains a foothold and impacts the business. Application whitelisting is listed as a Quick Win in the SANS Critical Security Controls list and the Australian Government Top 4 Mitigating Controls cybersecurity guidance. According to Australian Signals Directorate Deputy Director Steve Day, attackers have not stolen any sensitive data from government networks because of their adoption of the Top 4 mitigating controls.

But there are very effective protections that you can put in place, and they need not require new investment in technology or personnel. The Australian Defence Signals Directorate (DSD) has published guidance on the top 35 strategies to mitigate against targeted cyber intrusion and concluded that at least 85 % of the intrusions they responded to in 2011 and 2012 would have been prevented if only the top four of these mitigations had been in place.
These top four mitigations only require organizations to employ application whitelisting technology, maintain current, patched applications and operating systems and effectively restrict the use of administrative accounts.

Interoperability and Security

One of the common misconceptions about UAC and about Same-desktop Elevation in particular is that it prevents malware from being installed or from gaining administrative rights. First, malware can be written not to require administrative rights, and malware can be written to write just to areas in the user’s profile. More important, Same-desktop Elevation in UAC is not a security boundary and can be hijacked by unprivileged software that runs on the same desktop. Same-desktop Elevation should be considered a convenience feature, and from a security perspective, "Protected Administrator" should be considered the equivalent of "Administrator." By contrast, using Fast User Switching to log on to a different session by using an administrator account involves a security boundary between the administrator account and the standard user session.

One important thing to know is that UAC is not a security boundary. UAC helps people be more secure, […]
The most effective way to secure a system against malware is to run with standard user privileges.

[…] the primary purpose of elevation is not security, though, it’s convenience: […]

[…] this is also where we run into some of the limitations of UAC. Remember, there is no effective isolation; there is no security boundary that isolates processes on the same desktop.

Inside Windows Vista User Account Control:

It’s important to be aware that UAC elevations are conveniences and not security boundaries. A security boundary requires that security policy dictates what can pass through the boundary. User accounts are an example of a security boundary in Windows because one user can’t access the data belonging to another user without having that user’s permission.

The UAC’s Administrator Approval Mode, which is the default configuration, will allow most applications to run in a standard user mode, even when the user is an administrator. When the administrator privileges are needed, the UAC prompts the user for consent. While this is an effective way to reduce the attack surface, it does not provide the same level of control or security as using a standard user account.

• have the autoElevate property set in their (embedded) Application Manifest,
• are digitally signed by Microsoft with the Windows Publisher code signing certificate, and
• are stored in secure locations like %SystemRoot%\ and its subdirectories.

See UAC-a-mole alias qUACkery for some examples, their exploits and the mitigations.

To prevent the silent (automatic) elevation, set UAC to its highest level Always notify; to prevent any bypass, use a Standard User account and disable elevation requests there:

REGEDIT4

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System]
"ConsentPromptBehaviorAdmin"=dword:00000002 ; Prompt for consent on the secure desktop
"ConsentPromptBehaviorUser"=dword:00000000  ; Automatically deny elevation requests

Note: according to numbers published by Microsoft in their Security Intelligence Reports, about ½ to ¾ of all (some 600 million) Windows NT installations engaged in their malware telemetry reported only a single active user account.

Google’s Project Zero reported several bugs which allow to bypass UAC that Microsoft won’t fix: Issue 156 and Issue 220.

Also note that in combination with UAC Windows Explorer shows surprising and dangerous behaviour (documented in the MSKB article 950934) which generally impairs security and safety!

To detect directories with additional NTFS ACL entries created by Windows Explorer as well as (writable) files eventually created in these directories from your user account, start the Command Processor, run the following command lines and inspect their output, then remove the additional NTFS ACL entries:

2>NUL: (
ICACLs.exe "%SystemRoot%\*" /FindSID "%USERNAME%" /C /T
ICACLs.exe "%ProgramFiles%\*" /FindSID "%USERNAME%" /C /T
ICACLs.exe "%ProgramFiles(x86)%\*" /FindSID "%USERNAME%" /C /T
ICACLs.exe "%ProgramData%\*" /FindSID "%USERNAME%" /C /T
) | FindStr.exe /B /C:"SID "

ICACLs.exe "‹pathname›" /Remove:g "%USERNAME%"
…
ICACLs.exe "‹pathname›" /Remove:g "%USERNAME%"

Attrib.exe +H +S "‹directory›"
…
Attrib.exe +H +S "‹directory›"

FOR /D /R "%SystemRoot%" %? IN (*) DO @(DIR "%~?" /A 1>NUL: 2>NUL: || ECHO %?)
FOR /D /R "%ProgramFiles%" %? IN (*) DO @(DIR "%~?" /A 1>NUL: 2>NUL: || ECHO %?)
FOR /D /R "%ProgramFiles(x86)%" %? IN (*) DO @(DIR "%~?" /A 1>NUL: 2>NUL: || ECHO %?)
FOR /D /R "%ProgramData%" %? IN (*) DO @(DIR "%~?" /A 1>NUL: 2>NUL: || ECHO %?)

1>"%TMP%\SAFER.TMP" (
DIR "%SystemRoot%" /A:D /B /S
DIR "%ProgramFiles%" /A:D /B /S
DIR "%ProgramFiles(x86)%" /A:D /B /S
DIR "%ProgramData%" /A:D /B /S)
FOR /F "Delims= UseBackQ" %? IN ("%TMP%\SAFER.TMP") DO @(DIR "%~?" /A 1>NUL: 2>NUL: || ECHO %?)
ERASE "%TMP%\SAFER.TMP"

Prerequisites

• The permission for unprivileged users (really: members of the NT AUTHORITY\Authenticated Users or BUILTIN\Users groups) to create subdirectories in the root directory of the system drive must be removed from its NTFS ACL to prevent circumvention of Software Restriction Policies:

  ICACLs.exe %SystemDrive%\ /Deny *S-1-5-32-545:(AD,WD) /Remove:d *S-1-5-32-545 /Remove:g *S-1-5-11

• APPCERT.DLL must be installed on all versions of Windows NT to prevent circumvention of Software Restriction Policies!

• On Windows 10 and Windows 11 with the update 4052623 (to be) installed, the corresponding path rule must be uncommented in the setup script NTX_SAFER.INF before installation.

• On Windows 10 1709 alias Fall Creators Update, the update 4093105 fixes the bug that causes Microsoft Edge to stop after a few seconds.

• On Windows 10 1703 alias Creators Update, the update 4093117 fixes the bug that causes Microsoft Edge to stop after a few seconds.

• On Windows 7 and Windows Server 2008 R2, the hotfix 2532445, the hotfix 2894252, or the convenience rollup update 3125574 must be installed to prevent circumvention of Software Restriction Policies!

• On Windows 7, Windows Server 2008 R2 and newer versions of Windows NT, the optional update 977542 should be installed and the following Registry entry should be created to prevent unprivileged users from logging on in Safe Mode:

  REGEDIT4
  
  [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System]
  "SafeModeBlockNonAdmins"=dword:00000001 ; Disable 'Standard Users' in 'Safe Mode'

• On Windows Vista and Windows Server 2008, the optional update 969972 or one of the optional updates 2257986, 2414106 or 2812950 which contain a newer version of the file replaced by 969972 should be installed!

• On Windows Server 2003 and Windows Server 2003 R2, the optional update 973825 should be installed!

• On systems with AMD64 alias x64 processor architecture running Windows XP, Windows Server 2003 or Windows Server 2003 R2, the optional update 942589 must be installed to enable the special directory pathname %SystemRoot%\SysNative!

Loopholes, Limitations, Dependencies and Bugs

• An (unprivileged) adversary who is able to create a directory with the name of the Windows directory, typically Windows, followed by a trailing blank and/or with a file extension of only blanks, in the root directory of the system drive, typically C:\, can bypass Software Restriction Policies on all versions of Windows due to bugs in the Win32 functions FindFirstFile(), GetFullPathName(), GetLongPathName() and GetShortPathName() which are called to evaluate path rules!

  Note: removing the permission to create subdirectories in the root directory of the system drive for NT AUTHORITY\Authenticated Users and BUILTIN\Users prevents this bypass.

• An (unprivileged) adversary who is able to call the Win32 functions CreateProcess(), CreateProcessAsUser(), CreateProcessWithLogonW() and CreateProcessWithTokenW(), can bypass Software Restriction Policies on all versions of Windows!

  Note: installation of APPCERT.DLL prevents this bypass.

  Since Software Restriction Policies block the direct execution of Win32 applications, an adversary needs to find a way to run code inside one of the trusted Win32 applications installed on a victims computer, which typically means to (ab)use a vulnerability in these applications and compromise them.

• On Windows XP, Windows Server 2003, Windows Server 2003 R2, Windows Embedded POSReady 2009, Windows Embedded Standard 2009, Windows Vista and Windows Server 2008, Software Restriction Policies can be bypassed: the hotfixes 2532445 and 2894252 are not available for these versions of Windows NT!

  Note: an adversary must but be able to call the Win32 function LoadLibraryEx() to exercise this bypass.

  Since Software Restriction Policies block the direct execution of Win32 applications, an adversary needs to find a way to run code inside one of the trusted Win32 applications installed on a victims computer, which typically means to (ab)use a vulnerability in these applications and compromise them.

• On Windows XP, Windows Embedded POSReady 2009 and Windows Embedded Standard 2009, hash rules are not applied to DLLs.

  Note: this limitation is documented in the MSKB article 310791.

• On Windows 8 and later versions, registry path rules are not (properly) evaluated, especially in Modern Apps as well as Universal Windows Apps.

• Certificate rules are not applied to DLLs!

• Path rules with more than 133 character long paths are silently ignored!

• Rules defined with the nil GUID {00000000-0000-0000-0000-000000000000} are silently ignored!

• Software Restriction Policies control the execution of
  • Win32 applications loaded via the Win32 functions CreateProcess(), CreateProcessAsUser(), CreateProcessWithLogonW(), CreateProcessWithTokenW(), LoadModule() and WinExec(), independent of their file extension,
  • DLLs loaded via the Win32 functions LoadLibrary(), LoadLibraryEx() and LoadPackagedLibrary(), independent of their file extension,
  • files launched via the Win32 functions ShellExecute() and ShellExecuteEx(), depending on their file extension,
  i.e. all Win32 functions that load and execute Win32 portable executables or open files for execution.

• Unless disabled with the following Registry entry, Software Restriction Policies control the execution of scripts interpreted and run by the Windows Script Host, independent of their file extension:

  REGEDIT4
  
  [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Script Host\Settings]
  "UseWINSAFER"="0"

• Software Restriction Policies control the installation of Windows Installer packages and patches.

• Software Restriction Policies don’t control the execution of MS-DOS and 16-bit Windows applications: these run inside the NTVDM alias WOWEXEC subsystem, available only on systems with I386 alias x86 processor architecture.

  To disable the NTVDM and the WOWEXEC subsystem, set the Registry entry

  REGEDIT4
  
  [HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\AppCompat]
  "VDMDisallowed"=dword:00000001

  documented in the Security Advisory 979682 and the Security Bulletin MS13-063, plus the Registry entry

  REGEDIT4
  
  [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\WoW]
  "DisallowedPolicyDefault"=dword:00000001

  documented in the Security Bulletin MS10-098.

• Software Restriction Policies don’t control the execution of OS/2 or POSIX applications: these run inside their own optional and separate OS/2 or POSIX subsystem, either SFU (available for Windows XP and Windows Server 2003) or SUA (available for or included as Optional Component in Windows Server 2003 R2, Windows Vista, Windows Server 2008, Windows 7, Windows Server 2008 R2, Windows 8 and Windows Server 2012, but deprecated).

• Software Restriction Policies don’t control the interpretation and execution of code, macros or scripts inside Win32 applications unless these explicitly call the Win32 functions that implement SAFER:

  • the Windows Script Component Runtime, implemented in SCRObj.dll, called for example via RegSvr32.exe, can run arbitrary Windows Script Components alias Scriptlets, i.e. COM objects written in JScript, VBScript or any other scripting language supported by an installed Windows Script Engine;
  • PowerShell can run arbitrary scripts from its command line, can call arbitrary methods of the .NET runtime, can call arbitrary Win32 functions, can instantiate and call arbitrary COM objects;
  • a Java runtime engine can run arbitrary applets;
  • an Office Suite can run arbitrary macros;
  • a WWW browser, a Mail client, an Instant Messenger or a PDF viewer can run arbitrary JavaScript;
  • a Flash Player can run arbitrary ActionScript;
  • …
  Note: use the policies and settings of the respective host application to control its execution behaviour!
  For Internet Explorer for example, the MSKB articles 883256 and 915729 document how to disable execution of scripts.

Details

• Win32 portable executables, i.e. applications and DLLs, independent of their file extension, typically .exe, .com, .scr, .dll, .cpl, .ocx, .ime, .mui, .ax, .acm, .vcm, .tsp, .sys, .rll, .wll, .xll, .efi, …;
• packages, patches and transformations for the Windows Installer, previously known as Microsoft Installer (.msi, .msp and .mst);
• scripts for the Windows Script Host, independent of their file extension, typically .js, .jse, .vb, .vbs, .vbe, .ws, .wsc, .wsf, .wsh, …;
• COM scriptlets (.sct);
• PowerShell scripts and modules (.ps1 and .psm1);
• batch scripts (.bat and .cmd), independent of their file extension;
• setup scripts (.inf);
• HTML applications (.hta and .htc);
• …

Windows’ module loader, the Win32 functions CreateProcess*(), WinExec(), LoadModule(), LoadLibrary*() and LoadPackagedLibrary(), the Windows Installer, the Windows Script Host, the PowerShell interpreter and the Command Processor call the SAFER functions for every file they open for execution; only the Windows Explorer, i.e. the Win32 functions ShellExecute*(), evaluates the list of Designated File Types and calls the SAFER functions when a file extension matches.

Except on Home and Starter editions of Windows NT, this list of file extensions can be viewed and modified via the Local Security Policy snap-in of the Microsoft Management Console.

Note: the predefined list of file extensions is almost identical to the Unsafe File List of Internet Explorer, documented in the MSKB article 291369.

Caveat: the Local Security Policy snap-in reads SAFER settings and rules only from the file %SystemRoot%\System32\GroupPolicy\Machine\Registry.pol, not from the Registry; SAFER settings and rules written directly and only to the Registry therefore don’t show in the Local Security Policy snap-in!

If this file exists, modifications of the SAFER settings or rules written directly and only to the Registry will (periodically) be overwritten with the SAFER settings and rules from the file!

If this file contains neither SAFER settings nor rules (or does not exist), the Local Security Policy snap-in (creates it and) writes the default SAFER settings and rules to the file and to the Registry, thereby overwriting existing SAFER settings and rules in the Registry!
To avoid this, either run the program SRP2LGPO.EXE (available upon request) once to export all SAFER settings and rules from the Registry to the file %SystemRoot%\System32\GroupPolicy\Machine\Registry.pol, download the (empty) REGISTRY.POL REGISTRY.POL that contains the (missing) setting

REGEDIT4

[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Safer\CodeIdentifiers]
"Levels"=dword:00071000

COPY CON: "%TMP%\SAFER.TMP"
50 52 65 67 01 00 00 00 5b 00 53 00 4f 00 46 00   PReg....[.S.O.F.
54 00 57 00 41 00 52 00 45 00 5c 00 50 00 6f 00   T.W.A.R.E.\.P.o.
6c 00 69 00 63 00 69 00 65 00 73 00 5c 00 4d 00   l.i.c.i.e.s.\.M.
69 00 63 00 72 00 6f 00 73 00 6f 00 66 00 74 00   i.c.r.o.s.o.f.t.
5c 00 57 00 69 00 6e 00 64 00 6f 00 77 00 73 00   \.W.i.n.d.o.w.s.
5c 00 53 00 61 00 66 00 65 00 72 00 5c 00 43 00   \.S.a.f.e.r.\.C.
6f 00 64 00 65 00 49 00 64 00 65 00 6e 00 74 00   o.d.e.I.d.e.n.t.
69 00 66 00 69 00 65 00 72 00 73 00 00 00 3b 00   i.f.i.e.r.s...;.
4c 00 65 00 76 00 65 00 6c 00 73 00 00 00 3b 00   L.e.v.e.l.s...;.
04 00 00 00 3b 00 04 00 00 00 3b 00 00 10 07 00   ....;.....;.....
5d 00                                             ].
^Z
CertUtil.exe /DecodeHex /V "%TMP%\SAFER.TMP" "%SystemRoot%\System32\GroupPolicy\Machine\Registry.pol"
ERASE "%TMP%\SAFER.TMP"

        1 file(s) copied.
Input Length = 734
Output Length = 162
CertUtil: -decodehex command completed successfully.

Note: if the file %SystemRoot%\System32\GroupPolicy\Machine\Registry.pol is hidden, the Local Security Policy snap-in fails and displays a (bogus) error message access denied when applying changes!

Background Information

More than 15 years ago Microsoft introduced Software Restriction Policies alias SAFER and published the MSDN articles Using Software Restriction Policies to Protect Against Unauthorized Software Using Software Restriction Policies to Protect Against Unauthorized Software, Using Software Restriction Policies to Protect Against Unauthorized Software and How Software Restriction Policies Work �

Note: � � � �: �

From Strategies to Mitigate Cyber Security Incidents:

At least 85 % of the adversary techniques used in targeted cyber intrusions which ASD has visibility of could be mitigated by implementing the following mitigation strategies, referred to as the 'Top 4':
• use application whitelisting to help prevent malicious software and unapproved programs from running
[…]

From NCSC Applocker Guidance:

Application whitelisting is one of the best available protections against malware.

More than 15 years ago Microsoft introduced DEP alias W^X and enabled it by default.

�

But even today all (data) files created in the User Profiles, the %PUBLIC%\, %ProgramData%\ and almost all other data directories too are still executable: although not needed the (inheritable) NTFS ACLs of all these directories include execute permission for files!
And Software Restriction Policies are still not enabled by default! �

The immediate benefit of an NTFS ACL without execute permission or the default SAFER ruleset is: no (unintended) execution of files like invoice.pdf.exe etc. stored in data directories, so spreading malware to Windows NT systems becomes utterly useless.

If you want to try DEP in the NTFS filesystem for yourself, choose one of the following:

• Add the NTFS ACL entry (D;OIIO;WP;;;WD) meaning deny execution of files in this directory for everyone, inheritable to all files in all subdirectories for your own %USERPROFILE%\ directory (or all of them plus %ALLUSERSPROFILE%\ alias %ProgramData%\ and %PUBLIC%\ if you have administrative privileges).

  Note: deny ACL entries have precedence over allow ACL entries.

• Enable the default SAFER ruleset which allows execution (of *.exe) only in the directories %SystemRoot%\ and %SystemRoot%\System32\ and all executable files in the directory %ProgramFiles%\ and below.

  Note: this ruleset leaves but many loopholes!

  On systems with AMD64 alias x64 processor architecture, add path rules to allow execution of %SystemRoot%\SysWoW64\*.exe and %SystemRoot%\Sysnative\*.exe as well as %ProgramFiles(x86)%\.

  Note: without these additional rules, applications can’t execute applications for the other processor architecture!

• Follow the step-by-step instructions presented on How to make a disallowed-by-default Software Restriction Policy.

  Note: these instructions let Windows Apps (which were introduced with Windows 8) fail and leave multiple loopholes!

• Download and install the setup script XP_SAFER.INF (for Windows XP, including embedded editions, Windows Server 2003 and Windows Server 2003 R2), NT6_SAFER.INF (for Windows Vista and Windows 7 as well as Windows Server 2008 and Windows Server 2008 R2) or NTX_SAFER.INF (for Windows 8, Windows 8.1, Windows 10 and Windows 11 as well as Windows Server 2012, Windows Server 2012 R2, Windows Server 2016, Windows Server 2019 and Windows Server 2022) respectively.

Fallacies, Misconceptions and Myths

• SAFER has to be installed.

  Software Restriction Policies alias SAFER are a builtin feature of Windows XP and newer versions of Windows NT!

• SAFER is not available in Home editions.

  SAFER is available in all editions of Windows XP and newer versions of Windows NT!
  Home and Starter editions only lack the Local Security Policy snap-in of the Microsoft Management Console.

• SAFER is not suited for ordinary users.

  The SAFER ruleset configured by the setup scripts XP_SAFER.INF, NT6_SAFER.INF and NTX_SAFER.INF is made especially for ordinary (unprivileged alias standard) users who work with the applications installed on their computers!

• SAFER needs constant maintenance.

  The SAFER ruleset configured by the setup scripts XP_SAFER.INF, NT6_SAFER.INF and NTX_SAFER.INF allows to run all properly installed applications which meet the minimum requirements of the more than 25 years old Designed for Windows guidelines!

• I use UAC, I don’t need SAFER.

  UAC does not protect against execution of programs which run with standard user rights, for example ransomware like Locky!

• SAFER locks me out of my computer.

  The SAFER ruleset configured by the setup scripts XP_SAFER.INF, NT6_SAFER.INF and NTX_SAFER.INF restricts unprivileged users only, but not administrators, and does not restrict applications shipped with Windows NT!

  Additionally, Software Restriction Policies are not active in Safe Mode, where they can be disabled, for example via Registry Editor:

  REGEDIT4
  
  [HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Safer\CodeIdentifiers]
  ;"PolicyScope"=dword:00000001       ; exempt 'Administrators'
  "TransparentEnabled"=dword:00000000 ; no enforcement

Implementation and Build Details

All SAFER registry path rules which allow execution reference only Registry entries below HKEY_LOCAL_MACHINE to prevent users from tampering.
Note: never define a SAFER path rule that allows execution and references an environment variable or a Registry entry a user can write or modify!

SRP2LGPO.EXE, the program to export SAFER settings and rules from the Registry to the file %SystemRoot%\System32\GroupPolicy\Machine\Registry.pol, is a pure Win32 application, written in ANSI C, built with the Platform SDK for Windows Server 2003 R2 Microsoft Visual C++ Compiler 2010 SP1 from update 2519277, but without the MSVCRT libraries, for use on Windows 2000 and newer versions of Windows NT.

SRP2LGPO.EXE is available for the I386 alias x86, AMD64 alias x64 and IA64 processor architectures of Windows NT.

Download

Installation

Right-click the downloaded setup script *_SAFER.INF to display its context menu and click Install to run the installation.

Note: on systems with AMD64 alias x64 processor architecture, the installation must be run in the native (64-bit) execution environment!

Note: on Windows Vista and newer versions of Windows NT, InfDefaultInstall.exe, the application registered for the Install verb of *.inf files, requests administrative privileges.

Test

Note: the SAFER ruleset denies execution in all user-writable directories of default installations of Windows.

1. Log on to an unprivileged (standard) user account if possible, else to the user protected administrator account created during Windows Setup.

2. Right click on the desktop background to display the context menu, select New, then Text Document; change the file extension .txt to .cmd and press the Enter key.

3. Press the Enter key again to execute the just created (empty) batch script, or open it per double-click: a message box like that shown to the right must be displayed!
   

4. Start the Command Processor and run the following command lines to enumerate all (sub)directories beneath %SystemRoot%\, %ProgramFiles%\ and %ProgramFiles(x86)%\, attempt to create a (hardlink of the) batch script SAFER.BAT in each of them and (try to) execute it, attempt to create an Alternate Data Stream SAFER.VBS on each of them and (try to) execute it, logging the pathnames of directories where execution succeeds to the file %TMP%\SAFER.LOG:

   REM Copyright © 2004-2024, Stefan Kanthak <‍stefan‍.‍kanthak‍@‍nexgo‍.‍de‍>
   
   ECHO @ECHO %~dp0 1>"%TMP%\SAFER.TMP"
   MOVE "%TMP%\SAFER.TMP" "%SystemRoot%\Temp\SAFER.TMP" && (
   COPY NUL: "%TMP%\SAFER.LOG" && (
   DIR "%ProgramFiles%" /A:D /B /S 1>"%TMP%\SAFER.TMP"
   IF DEFINED ProgramFiles(x86) IF NOT "%ProgramFiles(x86)%" == "%ProgramFiles%" (
   DIR "%ProgramFiles(x86)%" /A:D /B /S 1>>"%TMP%\SAFER.TMP")
   DIR "%SystemRoot%" /A:D /B /S 1>>"%TMP%\SAFER.TMP"
   FOR /F "Delims= UseBackQ" %? IN ("%TMP%\SAFER.TMP") DO @(
   MKLINK /H "%~?\SAFER.BAT" "%SystemRoot%\Temp\SAFER.TMP" 2>NUL: && (
   CALL "%~?\SAFER.BAT" 1>>"%TMP%\SAFER.LOG"
   ERASE "%~?\SAFER.BAT")
   ECHO WScript.Echo WScript.ScriptFullName 1>"%~?:SAFER.VBS" && (
   "%SystemRoot%\System32\CSCRIPT.EXE" //NOLOGO "%~?:SAFER.VBS" 1>>"%TMP%\SAFER.LOG"))
   ERASE "%SystemRoot%\Temp\SAFER.TMP"
   ERASE "%TMP%\SAFER.TMP"
   TYPE "%TMP%\SAFER.LOG"))

   Note: the command lines can be copied and pasted as block into a Command Processor window!

   Caveat: the command lines can but detect user-writable directories only in paths where access permissions allow to list their contents!

           1 file(s) moved.
           1 file(s) copied.
   Hardlink created for C:\Windows\Tasks\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Hardlink created for C:\Windows\Temp\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Could Not Find C:\Windows\Temp\SAFER.BAT
   Hardlink created for C:\Windows\Tracing\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Hardlink created for C:\Windows\debug\WIA\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Hardlink created for C:\Windows\Registration\CRMLog\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Hardlink created for C:\Windows\System32\FxsTmp\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Hardlink created for C:\Windows\System32\Tasks\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Could Not Find C:\Windows\System32\Tasks\SAFER.BAT
   Hardlink created for C:\Windows\System32\catroot2\{F750E6C3-38EE-11D1-85E5-00C04FC295EE}\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Hardlink created for C:\Windows\System32\com\dmp\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Could Not Find C:\Windows\System32\com\dmp\SAFER.BAT
   Hardlink created for C:\Windows\System32\Spool\Printers\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Could Not Find C:\Windows\System32\Spool\Printers\SAFER.BAT
   Hardlink created for C:\Windows\System32\Spool\Drivers\color\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Hardlink created for C:\Windows\SysWOW64\FxsTmp\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Hardlink created for C:\Windows\SysWOW64\Tasks\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Could Not Find C:\Windows\SysWOW64\Tasks\SAFER.BAT
   Hardlink created for C:\Windows\SysWOW64\com\dmp\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Could Not Find C:\Windows\SysWOW64\com\dmp\SAFER.BAT
   ERASE "C:\Windows\Temp\SAFER.TMP"
   Could Not Find C:\Windows\Temp\SAFER.TMP

   Caveat: due to unnecessary access permissions requested by the builtin ERASE command the deletion of (the hardlink) SAFER.BAT fails in multiple user-writable directories; run the following command line to list the left-over files:

   FSUtil.exe HARDLINK LIST "%SystemRoot%\Temp\SAFER.TMP"

   Caveat: Alternate Data Streams can unfortunately not be deleted with the builtin ERASE command!

5. Create the text file SAFER.CMD with the following content in an arbitrary directory on the system drive %SystemDrive%\ where execution is allowed, for example the Windows directory %SystemRoot%\:

   REM Copyright © 2004-2024, Stefan Kanthak <‍stefan‍.‍kanthak‍@‍nexgo‍.‍de‍>
   
   SET DATE=
   DATE %DATE% 2>NUL:
   IF NOT ERRORLEVEL 1 EXIT /B
   
   ECHO @ECHO %%~dp0 1>"%TMP%\SAFER.TMP"
   MOVE "%TMP%\SAFER.TMP" "%SystemRoot%\Temp\SAFER.TMP"
   IF ERRORLEVEL 1 EXIT /B
   
   COPY NUL: "%TMP%\SAFER.LOG"
   IF ERRORLEVEL 1 EXIT /B
   
   DIR "%ProgramFiles%" /A:D /B /S 1>"%TMP%\SAFER.TMP"
   IF DEFINED ProgramFiles(x86) IF NOT "%ProgramFiles(x86)%" == "%ProgramFiles%" (
   DIR "%ProgramFiles(x86)%" /A:D /B /S 1>>"%TMP%\SAFER.TMP")
   DIR "%SystemRoot%" /A:D /B /S 1>>"%TMP%\SAFER.TMP"
   FOR /F "Delims= UseBackQ" %%? IN ("%TMP%\SAFER.TMP") DO @(
   MKLINK /H "%%~?\SAFER.BAT" "%SystemRoot%\Temp\SAFER.TMP" 2>NUL: && (
   CALL "%%~?\SAFER.BAT" 1>>"%TMP%\SAFER.LOG"
   ERASE "%%~?\SAFER.BAT")
   ECHO WScript.Echo WScript.ScriptFullName 1>"%%~?:SAFER.VBS" && (
   "%SystemRoot%\System32\CSCRIPT.EXE" //NOLOGO "%%~?:SAFER.VBS" 1>>"%TMP%\SAFER.LOG"))
   ERASE "%SystemRoot%\Temp\SAFER.TMP"
   ERASE "%TMP%\SAFER.TMP"
   TYPE "%TMP%\SAFER.LOG"
   EXIT /B

   The batch script SAFER.CMD enumerates all (sub)directories beneath %SystemRoot%\, %ProgramFiles%\ and %ProgramFiles(x86)%\, attempts to create a (hardlink of the secondary) batch script SAFER.BAT in each of them and (tries to) execute it, attempts to create an Alternate Data Stream SAFER.VBS on each of them and (tries to) execute it, logging the pathnames of directories where execution succeeds to the file %TMP%\SAFER.LOG.

   Caveat: the batch script SAFER.CMD can but detect user-writable directories only in paths where access permissions allow to list their contents!

6. Execute the batch script SAFER.CMD created in the previous step per double-click:

   REM Copyright © 2004-2024, Stefan Kanthak <‍stefan‍.‍kanthak‍@‍nexgo‍.‍de‍>
   
   DATE 08/15/2009 2>NUL:
   IF NOT ERRORLEVEL 1 EXIT /B
   
   ECHO @ECHO %~dp0  1>"C:\Users\Stefan\AppData\Local\Temp\SAFER.TMP"
   MOVE "C:\Users\Stefan\AppData\Local\Temp\SAFER.TMP" "C:\Windows\Temp"
           1 file(s) moved.
   IF ERRORLEVEL 1 EXIT /B
   
   COPY NUL: "C:\Users\Stefan\AppData\Local\Temp\SAFER.LOG"
           1 file(s) copied.
   IF ERRORLEVEL 1 EXIT /B
   
   DIR "C:\Program Files" /A:D /B /S  1>"C:\Users\Stefan\AppData\Local\Temp\SAFER.TMP"
   IF DEFINED ProgramFiles(x86) IF NOT "C:\Program Files (x86)" == "C:\Program Files" (
   DIR "C:\Program Files (x86)" /A:D /B /S  1>>"C:\Users\Stefan\AppData\Local\Temp\SAFER.TMP")
   DIR "C:\Windows" /A:D /B /S  1>>"C:\Users\Stefan\AppData\Local\Temp\SAFER.TMP"
   FOR /F "Delims= UseBackQ" %? IN ("C:\Users\Stefan\AppData\Local\Temp\SAFER.TMP") DO @(
   Hardlink created for C:\Windows\Tasks\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Hardlink created for C:\Windows\Temp\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Could Not Find C:\Windows\Temp\SAFER.BAT
   Hardlink created for C:\Windows\Tracing\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Hardlink created for C:\Windows\debug\WIA\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Hardlink created for C:\Windows\Registration\CRMLog\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Hardlink created for C:\Windows\System32\FxsTmp\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Hardlink created for C:\Windows\System32\Tasks\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Could Not Find C:\Windows\System32\Tasks\SAFER.BAT
   Hardlink created for C:\Windows\System32\catroot2\{F750E6C3-38EE-11D1-85E5-00C04FC295EE}\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Hardlink created for C:\Windows\System32\com\dmp\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Could Not Find C:\Windows\System32\com\dmp\SAFER.BAT
   Hardlink created for C:\Windows\System32\Spool\Printers\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Could Not Find C:\Windows\System32\Spool\Printers\SAFER.BAT
   Hardlink created for C:\Windows\System32\Spool\Drivers\color\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Hardlink created for C:\Windows\SysWOW64\FxsTmp\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Hardlink created for C:\Windows\SysWOW64\Tasks\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Could Not Find C:\Windows\SysWOW64\Tasks\SAFER.BAT
   Hardlink created for C:\Windows\SysWOW64\com\dmp\SAFER.BAT <<===>> C:\Windows\Temp\SAFER.TMP
   This program is blocked by group policy. For more information, contact your system administrator.
   Could Not Find C:\Windows\SysWOW64\com\dmp\SAFER.BAT
   ERASE "C:\Windows\Temp\SAFER.TMP"
   Could Not Find C:\Windows\Temp\SAFER.TMP
   ERASE "C:\Users\Stefan\AppData\Local\Temp\SAFER.TMP"
   TYPE "C:\Users\Stefan\AppData\Local\Temp\SAFER.LOG"
   EXIT /B

   Caveat: due to unnecessary access permissions requested by the builtin ERASE command the deletion of (the hardlink) SAFER.BAT fails in multiple user-writable directories; run the following command line to list the left-over files:

   FSUtil.exe HARDLINK LIST "%SystemRoot%\Temp\SAFER.TMP"

   Caveat: Alternate Data Streams can unfortunately not be deleted with the builtin ERASE command!

7. Open the file SAFER.LOG created in your %TMP% directory %LOCALAPPDATA%\Temp\ alias %USERPROFILE%\AppData\Local\Temp\: if it is not empty then either remove the user-writable directories listed there or add path rules to deny execution.

8. Create the text file SAFER.C with the following content in an arbitrary, preferable empty directory:

   // Copyright © 2004-2024, Stefan Kanthak <‍stefan‍.‍kanthak‍@‍nexgo‍.‍de‍>
   
   #define STRICT
   #define UNICODE
   #define WIN32_LEAN_AND_MEAN
   
   #include <windows.h>
   #include <winsafer.h>
   #include <wintrust.h>
   
   #if ANYSIZE_ARRAY != 1
   #error ANYSIZE_ARRAY must be defined as 1!
   #endif
   
   #define wmemcpy	__movsw
   
   __declspec(safebuffers)
   BOOL	CDECL	PrintConsole(HANDLE hConsole, [SA_FormatString(Style="printf")] LPCWSTR lpFormat, ...)
   {
   	WCHAR	szOutput[1024];
   	DWORD	dwOutput;
   	DWORD	dwConsole;
   
   	va_list	vaInput;
   	va_start(vaInput, lpFormat);
   
   	dwOutput = wvsprintf(szOutput, lpFormat, vaInput);
   
   	va_end(vaInput);
   
   	if (dwOutput == 0)
   		return FALSE;
   
   	if (!WriteConsole(hConsole, szOutput, dwOutput, &dwConsole, NULL))
   		return FALSE;
   
   	return dwConsole == dwOutput;
   }
   
   WCHAR	szPathName[32768] = L"";
   
   const	SAFER_CODE_PROPERTIES	scp = {sizeof(scp),
   				       SAFER_CRITERIA_AUTHENTICODE | SAFER_CRITERIA_IMAGEHASH | SAFER_CRITERIA_IMAGEPATH,
   				       szPathName,
   				       (HANDLE) NULL,
   				       0,
   				       {0},
   				       0,
   				       {0},
   				       (ALG_ID) 0,
   				       (LPBYTE) NULL,
   				       HWND_DESKTOP,
   				       WTD_UI_NONE};
   
   DWORD	WINAPI	SRPLevel(HANDLE hConsole)
   {
   	SAFER_LEVEL_HANDLE	slh = INVALID_HANDLE_VALUE;
   
   	DWORD	dwLevelId = ~0UL;
   	DWORD	dw;
   
   	if (!SaferIdentifyLevel(1, &scp, &slh, NULL))
   		PrintConsole(hConsole,
   		             L"SaferIdentifyLevel() returned error %lu for path \'%ls\'\n",
   		             GetLastError(), scp.ImagePath);
   	else
   	{
   		if (!SaferGetLevelInformation(slh, SaferObjectLevelId, &dwLevelId, sizeof(dwLevelId), &dw))
   			PrintConsole(hConsole,
   			             L"SaferGetLevelInformation() returned error %lu for path \'%ls\'\n",
   			             GetLastError(), scp.ImagePath);
   
   		if (!SaferCloseLevel(slh))
   			PrintConsole(hConsole,
   			             L"SaferCloseLevel() returned error %lu\n",
   			             GetLastError());
   	}
   
   	return dwLevelId;
   }
   
   typedef	struct	_ace
   {
   	ACE_HEADER	header;
   	ACCESS_MASK	mask;
   	SID		trustee;
   } ACE;
   
   const	struct	_acl
   {
   	ACL	acl;
   	ACE	ace[ANYSIZE_ARRAY];
   } dacl = {{ACL_REVISION, 0, sizeof(dacl), ANYSIZE_ARRAY, 0},
   #if 0	// (A;NP;0x1f0000;;;AU)
             {{{ACCESS_ALLOWED_ACE_TYPE, NO_PROPAGATE_INHERIT_ACE, sizeof(ACE)},
               STANDARD_RIGHTS_ALL,
               {SID_REVISION, ANYSIZE_ARRAY, SECURITY_NT_AUTHORITY, SECURITY_AUTHENTICATED_USER_RID}}}};
   #else	// (A;NP;0x1f0000;;;OW)
             {{{ACCESS_ALLOWED_ACE_TYPE, NO_PROPAGATE_INHERIT_ACE, sizeof(ACE)},
               STANDARD_RIGHTS_ALL,
               {SID_REVISION, ANYSIZE_ARRAY, SECURITY_CREATOR_SID_AUTHORITY, SECURITY_CREATOR_OWNER_RIGHTS_RID}}}};
   #endif
   
   const	SECURITY_DESCRIPTOR	sd = {SECURITY_DESCRIPTOR_REVISION,
   				      0,
   				      SE_DACL_PRESENT | SE_DACL_PROTECTED | SE_GROUP_DEFAULTED | SE_OWNER_DEFAULTED | SE_SACL_DEFAULTED,
   				      (SID *) NULL,
   				      (SID *) NULL,
   				      (ACL *) NULL,
   				      &dacl};
   
   const	SECURITY_ATTRIBUTES	sa = {sizeof(sa),
   				      &sd,
   				      FALSE};
   
   __declspec(safebuffers)
   DWORD	WINAPI	Traverse(HANDLE hConsole, DWORD dwPathName)
   {
   	DWORD	dwFileName;
   	DWORD	dwError = ERROR_SUCCESS;
   	LPWSTR	lpPathName = szPathName + dwPathName;
   	HANDLE	hFindFile;
   	HANDLE	hStream;
   	DWORD	dwStream = 0;
   	HANDLE	hFile;
   	DWORD	dwFile = 0;
   
   	WIN32_FIND_DATA	wfd;
   #if 0
   	wcscpy(lpPathName, L":SAFER.TMP");
   #else
   	wmemcpy(lpPathName, L":SAFER.TMP", sizeof(":SAFER.TMP"));
   #endif
   	hStream = CreateFile(szPathName,
   	                     FILE_WRITE_DATA,
   	                     FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE,
   	                     (LPSECURITY_ATTRIBUTES) NULL,
   	                     CREATE_ALWAYS,
   #if 0	// NOTE: FILE_FLAG_DELETE_ON_CLOSE requires DELETE access and permission!
   	                     FILE_FLAG_DELETE_ON_CLOSE,
   #elif 0
   	                     FILE_ATTRIBUTE_TEMPORARY,
   #else
   	                     FILE_ATTRIBUTE_NORMAL,
   #endif
   	                     (HANDLE) NULL);
   
   	if (hStream != INVALID_HANDLE_VALUE)
   	{
   		if (!WriteFile(hStream,
   		               L"\xFEFF",	// UTF-16LE byte order mark
   		               sizeof(L'\xFEFF'),
   		               &dwStream,
   		               (LPOVERLAPPED) NULL))
   			PrintConsole(hConsole,
   			             L"WriteFile() returned error %lu for alternate data stream \'%ls\'\n",
   			             GetLastError(), szPathName);
   		else
   			if (dwStream != sizeof(L'\xFEFF'))
   				PrintConsole(hConsole,
   				             L"WriteFile() failed, %lu of %lu bytes written to alternate data stream \'%ls\'\n",
   				             dwStream, sizeof(L'\xFEFF'), szPathName);
   			else
   				PrintConsole(hConsole,
   				             L"%lu\t%ls\n",
   				             SRPLevel(hConsole), szPathName);
   
   		if (!CloseHandle(hStream))
   			PrintConsole(hConsole,
   			             L"CloseHandle() returned error %lu\n",
   			             GetLastError());
   
   		if (!DeleteFile(szPathName))
   			PrintConsole(hConsole,
   			             L"DeleteFile() returned error %lu for alternate data stream \'%ls\'\n",
   			             GetLastError(), szPathName);
   	}
   	else
   	{
   		dwError = GetLastError();
   
   		if (dwError != ERROR_ACCESS_DENIED)
   			PrintConsole(hConsole,
   			             L"CreateFile() returned error %lu for alternate data stream \'%ls\'\n",
   			             dwError, szPathName);
   		else
   			dwError = ERROR_SUCCESS;
   	}
   #if 0
   	wcscpy(lpPathName, L"\\SAFER.TMP");
   #elif 0
   	wmemcpy(lpPathName, L"\\SAFER.TMP", sizeof("\\SAFER.TMP"));
   #else
   	lpPathName[0] = L'\\';
   #endif
   	hFile = CreateFile(szPathName,
   	                   FILE_WRITE_DATA,
   	                   FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE,
   #if 0
   	                   (LPSECURITY_ATTRIBUTES) NULL,
   #else
   	                   &sa,
   #endif
   	                   CREATE_ALWAYS,
   #if 0	// NOTE: FILE_FLAG_DELETE_ON_CLOSE requires DELETE access and permission!
   	                   FILE_FLAG_DELETE_ON_CLOSE,
   #elif 0
   	                   FILE_ATTRIBUTE_TEMPORARY,
   #else
   	                   FILE_ATTRIBUTE_NORMAL,
   #endif
   	                   (HANDLE) NULL);
   
   	if (hFile != INVALID_HANDLE_VALUE)
   	{
   		if (!WriteFile(hFile,
   		               L"\xFEFF",	// UTF-16LE byte order mark
   		               sizeof(L'\xFEFF'),
   		               &dwFile,
   		               (LPOVERLAPPED) NULL))
   			PrintConsole(hConsole,
   			             L"WriteFile() returned error %lu for file \'%ls\'\n",
   			             GetLastError(), szPathName);
   		else
   			if (dwFile != sizeof(L'\xFEFF'))
   				PrintConsole(hConsole,
   				             L"WriteFile() failed, %lu of %lu bytes written to file \'%ls\'\n",
   				             dwFile, sizeof(L'\xFEFF'), szPathName);
   			else
   				PrintConsole(hConsole,
   				             L"%lu\t%ls\n",
   				             SRPLevel(hConsole), szPathName);
   
   		if (!CloseHandle(hFile))
   			PrintConsole(hConsole,
   			             L"CloseHandle() returned error %lu\n",
   			             GetLastError());
   
   		if (!DeleteFile(szPathName))
   			PrintConsole(hConsole,
   			             L"DeleteFile() returned error %lu for file \'%ls\'\n",
   			             GetLastError(), szPathName);
   	}
   	else
   	{
   		dwError = GetLastError();
   
   		if (dwError != ERROR_ACCESS_DENIED)
   			PrintConsole(hConsole,
   			             L"CreateFile() returned error %lu for file \'%ls\'\n",
   			             dwError, szPathName);
   		else
   			dwError = ERROR_SUCCESS;
   
   		if (CreateDirectory(szPathName,
   #if 0
   		                    (LPSECURITY_ATTRIBUTES) NULL))
   #else
   		                    &sa))
   #endif
   		{
   #if 0
   			wcscpy(lpPathName + sizeof("SAFER"), L"\\TMP");
   #elif 0
   			wmemcpy(lpPathName + sizeof("SAFER"), L"\\TMP", sizeof("\\TMP"));
   #else
   			lpPathName[sizeof("SAFER")] = L'\\';
   #endif
   			PrintConsole(hConsole,
   			             L"%lu\t%ls\n",
   			             SRPLevel(hConsole), szPathName);
   #if 0
   			wcscpy(lpPathName + sizeof("SAFER"), L".TMP");
   #elif 0
   			wmemcpy(lpPathName + sizeof("SAFER"), L".TMP", sizeof(".TMP"));
   #else
   			lpPathName[sizeof("SAFER")] = L'.';
   #endif
   			if (!RemoveDirectory(szPathName))
   				PrintConsole(hConsole,
   				             L"RemoveDirectory() returned error %lu for directory \'%ls\'\n",
   				             GetLastError(), szPathName);
   		}
   		else
   		{
   			dwError = GetLastError();
   
   			if (dwError != ERROR_ACCESS_DENIED)
   				PrintConsole(hConsole,
   				             L"CreateDirectory() returned error %lu for directory \'%ls\'\n",
   				             dwError, szPathName);
   			else
   				dwError = ERROR_SUCCESS;
   		}
   	}
   #if 0
   	wcscpy(lpPathName, L"\\*");
   #elif 0
   	wmemcpy(lpPathName, L"\\*", sizeof("\\*"));
   #else
   //	lpPathName[0] = L'\\';
   	lpPathName[1] = L'*';
   	lpPathName[2] = L'\0';
   #endif
   	hFindFile = FindFirstFile(szPathName, &wfd);
   
   	if (hFindFile != INVALID_HANDLE_VALUE)
   	{
   		do
   		{
   			if (((wfd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != FILE_ATTRIBUTE_DIRECTORY)
   			 || ((wfd.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) == FILE_ATTRIBUTE_REPARSE_POINT))
   				continue;
   #if 0
   			if ((wcscmp(wfd.cFileName, L".") == 0)
   			 || (wcscmp(wfd.cFileName, L"..") == 0))
   				continue;
   #elif 0
   			if ((wmemcmp(wfd.cFileName, L".", sizeof(".")) == 0)
   			 || (wmemcmp(wfd.cFileName, L"..", sizeof("..")) == 0))
   				continue;
   #else
   			if ((wfd.cFileName[0] == L'.')
   			 && (wfd.cFileName[1] == L'\0'))
   				continue;
   
   			if ((wfd.cFileName[0] == L'.')
   			 && (wfd.cFileName[1] == L'.')
   			 && (wfd.cFileName[2] == L'\0'))
   				continue;
   #endif
   			dwFileName = wcslen(wfd.cFileName);
   #if 0
   			wcscpy(lpPathName + 1, wfd.cFileName);
   #else
   			wmemcpy(lpPathName + 1, wfd.cFileName, dwFileName);
   #endif
   			dwError = Traverse(hConsole, dwPathName + 1 + dwFileName);
   		}
   		while (FindNextFile(hFindFile, &wfd));
   #if 0
   		wcscpy(lpPathName, L"\\*");
   #elif 0
   		wmemcpy(lpPathName, L"\\*", sizeof("\\*"));
   #else
   		lpPathName[1] = L'*';
   		lpPathName[2] = L'\0';
   #endif
   		dwError = GetLastError();
   
   		if (dwError != ERROR_NO_MORE_FILES)
   			PrintConsole(hConsole,
   			             L"FindNextFile() returned error %lu for path \'%ls\'\n",
   			             dwError, szPathName);
   		else
   			dwError = ERROR_SUCCESS;
   
   		if (!FindClose(hFindFile))
   			PrintConsole(hConsole,
   			             L"FindClose() returned error %lu for path \'%ls\'\n",
   			             GetLastError(), szPathName);
   	}
   	else
   	{
   		dwError = GetLastError();
   
   		if (dwError != ERROR_FILE_NOT_FOUND)
   			PrintConsole(hConsole,
   			             L"FindFirstFile() returned error %lu for path \'%ls\'\n",
   			             dwError, szPathName);
   		else
   			dwError = ERROR_SUCCESS;
   	}
   
   //	lpPathName[0] = L'\0';
   
   	return dwError;
   }
   
   __declspec(noreturn)
   VOID	CDECL	wmainCRTStartup(VOID)
   {
   #ifndef _WIN64
   	BOOL	bWoW64;
   	LPVOID	lpWoW64;
   #endif
   	DWORD	dwPathName;
   	DWORD	dwError;
   	HANDLE	hConsole = GetStdHandle(STD_ERROR_HANDLE);
   
   	if (hConsole == INVALID_HANDLE_VALUE)
   		dwError = GetLastError();
   	else
   	{
   		dwPathName = GetSystemWindowsDirectory(szPathName, sizeof(szPathName) / sizeof(*szPathName));
   
   		if (dwPathName == 0)
   			PrintConsole(hConsole,
   			             L"GetSystemWindowsDirectory() returned error %lu\n",
   			             dwError = GetLastError());
   		else
   #ifdef _WIN64
   			dwError = Traverse(hConsole, dwPathName);
   #else
   			if (!IsWow64Process(GetCurrentProcess(), &bWoW64))
   				PrintConsole(hConsole,
   				             L"IsWow64Process() returned error %lu\n",
   				             dwError = GetLastError());
   			else
   				if (!bWoW64)
   					dwError = Traverse(hConsole, dwPathName);
   				else
   					if (!Wow64DisableWow64FsRedirection(&lpWoW64))
   						PrintConsole(hConsole,
   						             L"Wow64DisableWow64FsRedirection() returned error %lu\n",
   						             dwError = GetLastError());
   					else
   					{
   						dwError = Traverse(hConsole, dwPathName);
   
   						if (!Wow64RevertWow64FsRedirection(lpWoW64))
   							PrintConsole(hConsole,
   							             L"Wow64RevertWow64FsRedirection() returned error %lu\n",
   							             GetLastError());
   					}
   #endif
   	}
   
   	ExitProcess(dwError);
   }

9. Build the console application SAFER.COM from the source file SAFER.C created in the previous step:

   SET CL=/GAFy /Oxy /W4 /Zl
   SET LINK=/DEFAULTLIB:ADVAPI32.LIB /DEFAULTLIB:KERNEL32.LIB /DEFAULTLIB:USER32.LIB /ENTRY:wmainCRTStartup /LARGEADDRESSAWARE /NOCOFFGRPINFO /OSVERSION:5.1 /SUBSYSTEM:CONSOLE /SWAPRUN:CD,NET /VERSION:0.815
   CL.EXE /FeSAFER.COM SAFER.C

   The console application SAFER.COM enumerates all (sub)directories underneath the Windows directory %SystemRoot%\, attempts to create an Alternate Data Stream SAFER.TMP on each of them, then either a file or a subdirectory SAFER.TMP in each of them, queries the SAFER level for every file written or directory created and prints it followed by the pathname.

   For details and reference see the MSDN articles Compiler Options and Linker Options.

   Note: if necessary, see the MSDN article Use the Microsoft C++ toolset from the command line for an introduction.

   Note: SAFER.COM is a pure Win32 console application and builds without the MSVCRT libraries.

   Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 16.00.40219.01 for 80x86
   Copyright (C) Microsoft Corporation.  All rights reserved.
   
   SAFER.C
   SAFER.C(62) : warning C4090: 'function' : different 'const' qualifiers
   SAFER.C(110) : warning C4090: 'initializing' : different 'const' qualifiers
   SAFER.C(113) : warning C4090: 'initializing' : different 'const' qualifiers
   SAFER.C(202) : warning C4090: 'function' : different 'const' qualifiers
   SAFER.C(259) : warning C4090: 'function' : different 'const' qualifiers
   
   Microsoft (R) Incremental Linker Version 10.00.40219.386
   Copyright (C) Microsoft Corporation.  All rights reserved.
   
   …

10. Create the text file SAFER.XML with the following content in the directory where you built the console application SAFER.COM:

    <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
    <!-- Copyright (C) 2004-2024, Stefan Kanthak -->
    <assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1">
        <assemblyIdentity name="eSKamation.Tools.SAFER Loophole Detector Command" processorArchitecture="*" type="win32" version="0.8.1.5" />
        <application xmlns="urn:schemas-microsoft-com:asm.v3">
            <windowsSettings>
                <longPathAware xmlns="http://schemas.microsoft.com/SMI/2016/WindowsSettings">true</longPathAware>
            </windowsSettings>
        </application>
        <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
            <application>
                <supportedOS Id="{e2011457-1546-43c5-a5fe-008deee3d3f0}" />
                <supportedOS Id="{35138b9a-5d96-4fbd-8e2d-a2440225f93a}" />
                <supportedOS Id="{4a2f28e3-53b9-4441-ba9c-d69d4a4a6e38}" />
                <supportedOS Id="{1f676c76-80e1-4239-95bb-83d0f6d0da78}" />
                <supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}" />
            </application>
        </compatibility>
        <description>SAFER Loophole Detector Command</description>
        <trustInfo xmlns="urn:schemas-microsoft-com:asm.v2">
            <security>
                <requestedPrivileges>
                    <requestedExecutionLevel level="asInvoker" uiAccess="false" />
                </requestedPrivileges>
            </security>
        </trustInfo>
    </assembly>

    Note: an Application Manifest is mandatory to disable the filesystem virtualisation for 32-bit processes and to enable long pathnames for the functions of the Win32 API! New UAC Technologies for Windows Vista

11. Embed the application manifest SAFER.XML created in the previous step in the console application SAFER.COM:

    MT.EXE /CANONICALIZE /MANIFEST SAFER.XML /OUTPUTRESOURCE:SAFER.COM

    Mt.exe

    Microsoft (R) Manifest Tool version 6.1.7716.0
    Copyright (c) Microsoft Corporation 2009.
    All rights reserved.

12. Finally execute the console application SAFER.COM built in the previous steps as unprivileged (standard) user to detect all directories beneath the Windows directory %SystemRoot%\ where users can write and (still) execute:

    .\SAFER.COM

    Caveat: the console application SAFER.COM can but detect user-writable directories only in paths where access permissions allow to list their contents!

    FindFirstFile() returned error 5 for path 'C:\Windows\appcompat\Programs\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\CSC\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\LiveKernelReports\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\Logs\SystemRestore\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\ModemLogs\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\PLA\Reports\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\PLA\Rules\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\PLA\Templates\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\Prefetch\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\Provisioning\Autopilot\*'
         0	C:\Windows\Registration\CRMLog:SAFER.TMP
    DeleteFile() returned error 5 for alternate data stream 'C:\Windows\Registration\CRMLog:SAFER.TMP'
         0	C:\Windows\Registration\CRMLog\SAFER.TMP
    FindFirstFile() returned error 5 for path 'C:\Windows\Resources\Themes\aero\VSCache\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\security\audit\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\security\cap\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\ServiceProfiles\LocalService\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\ServiceProfiles\NetworkService\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\ServiceState\*'
         0	C:\Windows\System32\Com\dmp:SAFER.TMP
    DeleteFile() returned error 5 for alternate data stream 'C:\Windows\System32\Com\dmp:SAFER.TMP'
         0	C:\Windows\System32\Com\dmp\SAFER.TMP
    FindFirstFile() returned error 5 for path 'C:\Windows\System32\Com\dmp\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\System32\config\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\System32\Configuration\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\System32\drivers\DriverData\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\System32\DriverState\*'
         0	C:\Windows\System32\FxsTmp:SAFER.TMP
    DeleteFile() returned error 5 for alternate data stream 'C:\Windows\System32\FxsTmp:SAFER.TMP'
         0	C:\Windows\System32\FxsTmp\SAFER.TMP
    FindFirstFile() returned error 5 for path 'C:\Windows\System32\ias\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\System32\LogFiles\WMI\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\System32\MsDtc\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\System32\networklist\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\System32\SleepStudy\*'
         0	C:\Windows\System32\spool\drivers\color:SAFER.TMP
    DeleteFile() returned error 5 for alternate data stream 'C:\Windows\System32\spool\drivers\color:SAFER.TMP'
         0	C:\Windows\System32\spool\drivers\color\SAFER.TMP
         0	C:\Windows\System32\spool\PRINTERS:SAFER.TMP
    DeleteFile() returned error 5 for alternate data stream 'C:\Windows\System32\spool\PRINTERS:SAFER.TMP'
         0	C:\Windows\System32\spool\PRINTERS\SAFER.TMP
    FindFirstFile() returned error 5 for path 'C:\Windows\System32\spool\PRINTERS\*'
         0	C:\Windows\System32\spool\SERVERS:SAFER.TMP
    DeleteFile() returned error 5 for alternate data stream 'C:\Windows\System32\spool\SERVERS:SAFER.TMP'
         0	C:\Windows\System32\spool\SERVERS\SAFER.TMP
    FindFirstFile() returned error 5 for path 'C:\Windows\System32\spool\SERVERS\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\System32\sru\*'
         0	C:\Windows\System32\Tasks:SAFER.TMP
    DeleteFile() returned error 5 for alternate data stream 'C:\Windows\System32\Tasks:SAFER.TMP'
         0	C:\Windows\System32\Tasks\SAFER.TMP
    FindFirstFile() returned error 5 for path 'C:\Windows\System32\Tasks\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\System32\wbem\MOF\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\System32\WDI\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\SystemTemp\*'
         0	C:\Windows\SysWOW64\Com\dmp:SAFER.TMP
    DeleteFile() returned error 5 for alternate data stream 'C:\Windows\SysWOW64\Com\dmp:SAFER.TMP'
         0	C:\Windows\SysWOW64\Com\dmp\SAFER.TMP
    FindFirstFile() returned error 5 for path 'C:\Windows\SysWOW64\Com\dmp\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\SysWOW64\config\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\SysWOW64\Configuration\*'
         0	C:\Windows\SysWOW64\FxsTmp:SAFER.TMP
    DeleteFile() returned error 5 for alternate data stream 'C:\Windows\SysWOW64\FxsTmp:SAFER.TMP'
         0	C:\Windows\SysWOW64\FxsTmp\SAFER.TMP
    FindFirstFile() returned error 5 for path 'C:\Windows\SysWOW64\Msdtc\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\SysWOW64\networklist\*'
    FindFirstFile() returned error 5 for path 'C:\Windows\SysWOW64\sru\*'
         0	C:\Windows\SysWOW64\Tasks:SAFER.TMP
    DeleteFile() returned error 5 for alternate data stream 'C:\Windows\SysWOW64\Tasks:SAFER.TMP'
         0	C:\Windows\SysWOW64\Tasks\SAFER.TMP
    FindFirstFile() returned error 5 for path 'C:\Windows\SysWOW64\Tasks\*'
         0	C:\Windows\Tasks:SAFER.TMP
    DeleteFile() returned error 5 for alternate data stream 'C:\Windows\Tasks:SAFER.TMP'
         0	C:\Windows\Tasks\SAFER.TMP
         0	C:\Windows\Temp:SAFER.TMP
    DeleteFile() returned error 5 for alternate data stream 'C:\Windows\Temp:SAFER.TMP'
         0	C:\Windows\Temp\SAFER.TMP
    FindFirstFile() returned error 5 for path 'C:\Windows\Temp\*'
         0	C:\Windows\tracing:SAFER.TMP
    DeleteFile() returned error 5 for alternate data stream 'C:\Windows\tracing:SAFER.TMP'
         0	C:\Windows\tracing\SAFER.TMP

    Caveat: deletion of the Alternate Data Stream SAFER.TMP from some user-writable directories fails due to their access permissions!

Update

Upgrade

Deinstallation

On Windows XP and Windows Server 2003, open the Add/Remove Programs applet of the Control Panel, tick the checkbox Updates, select the entry Softwarebeschränkungsrichtlinien für 'Windows XP/2003 [R2]' underneath Systemkonfiguration and click the Remove button.

On Windows Vista and newer versions of Windows NT, open the Control Panel and click the entry View installed updates underneath the Programs and Features or Programs category.
In Installed Updates select the entry Softwarebeschränkungsrichtlinien für 'Windows Vista/2008 [R2]/7' underneath Systemkonfiguration and click the Uninstall menu entry.

Note: deinstallation neither removes the file %SystemRoot%\System32\GroupPolicy\Machine\Registry.pol nor any SAFER settings and rules from it.

Bugs

REGEDIT4

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System]
"SafeModeBlockNonAdmins"=dword:00000001 ; Disable 'Standard Users' in 'Safe Mode'

ATTENTION: versions of NTX_SAFER.INF prior to 2022-07-29 had a bug on 64-bit installations: instead to add the path rules %SystemRoot%\System32\Microsoft\Crypto\RSA\MachineKeys, %SystemRoot%\System32\Microsoft\Crypto\RSA\MachineKeys:* and %SystemRoot%\SysNative\Microsoft\Crypto\RSA\MachineKeys:* it added the latter thrice!

Contact

Use the X.509 certificate to send S/MIME encrypted mail.

Note: email in weird format and without a proper sender name is likely to be discarded!

I dislike HTML (and even weirder formats too) in email, I prefer to receive plain text.
I also expect to see your full (real) name as sender, not your nickname.
I abhor top posts and expect inline quotes in replies.

Terms and Conditions

• The software and the documentation on this site are provided as is without any warranty, neither express nor implied.
  In no event will the author be held liable for any damage(s) arising from the use of the software or the documentation.
• Permission is granted to use the current version of the software and the current version of the documentation solely for personal private and non-commercial purposes.
  An individuals use of the software or the documentation in his or her capacity or function as an agent, (independent) contractor, employee, member or officer of a business, corporation or organisation (commercial or non-commercial) does not qualify as personal private and non-commercial purpose.
• Without written approval from the author the software or the documentation must not be used for a business, for commercial, corporate, governmental, military or organisational purposes of any kind, or in a commercial, corporate, governmental, military or organisational environment of any kind.
• Redistribution of the software and the documentation is allowed only in unmodified form of its current version and free of charge.

Data Protection Declaration

The web service is operated and provided by

The web service provider stores a session cookie in the web browser and records every visit of this web site with the following data in an access log on their server(s):

• the (pseudonymised) IP address;
• the date and time of the request;
• the URL of the requested web page or file;
• the Referer and User-Agent HTTP headers sent by the web browser;
• the result (success or failure) of the request;
• the amount of data received and sent.