AppLocker explained

AppLocker is an application whitelisting technology introduced with Microsoft's Windows 7 operating system. It allows restricting which programs users can execute based on the program's path, publisher, or hash,^[1] and in an enterprise can be configured via Group Policy.

Summary

Windows AppLocker allows administrators to control which executable files are denied or allowed to execute. With AppLocker, administrators are able to create rules based on file names, publishers or file location that will allow certain files to execute. Unlike the earlier Software Restriction Policies, which was originally available for Windows XP and Windows Server 2003,^[2] AppLocker rules can apply to individuals or groups. Policies are used to group users into different enforcement levels. For example, some users can be added to an 'audit' policy that will allow administrators to see the rule violations before moving that user to a higher enforcement level.

Bypass techniques

There are several generic techniques for bypassing AppLocker:

• Writing an unapproved program to a whitelisted location.
• Using a whitelisted program as a delegate to launch an unapproved program.^{[8] [9] [10] [11]}
• Hijacking the DLLs loaded by a trusted application in an untrusted directory.^[12]

References

1. Web site: AppLocker. Microsoft TechNet. Microsoft. 23 August 2012.
2. Web site: Using Software Restriction Policies to Protect Against Unauthorized Software. Microsoft TechNet. Microsoft. 27 July 2017.
3. Web site: Windows Versions That Support AppLocker . Microsoft . 27 July 2017.
4. Web site: Introducing Windows 8 Enterprise and Enhanced Software Assurance for Today's Modern Workforce . Windows for your Business . Microsoft . 18 April 2012 . 22 November 2012 . Erwin . Visser . 25 December 2012 . https://web.archive.org/web/20121225113214/http://blogs.windows.com/windows/b/business/archive/2012/04/18/introducing-windows-8-enterprise-and-enhanced-software-assurance-for-today-s-modern-workforce.aspx . dead .
5. Web site: Microsoft shows OEMs how to market Windows 10; talks features and SKUs . Dudau . Vlad . 10 June 2015 . Neowin . Neowin LLC . 19 June 2015.
6. Web site: Find out which Windows is right for you . Microsoft . Microsoft Inc . 2 July 2015.
7. Web site: Removal of Windows edition checks for AppLocker . Microsoft . Microsoft Inc . 22 February 2023.
8. Web site: AppLocker Bypass – InstallUtil . Penetration Testing Lab . 8 May 2017 . 27 July 2017.
9. Web site: AppLocker Bypass Techniques . Evi1cg's blog. 27 July 2017.
10. Web site: How to Bypass Windows AppLocker. Hacking Tutorial. 19 April 2017 . 27 July 2017.
11. Web site: caseysmithrc/gethelp.cs. Github Gist. 14 May 2019. 14 May 2019. https://web.archive.org/web/20190514145515/https://gist.github.com/caseysmithrc/0b40f1ec0340edd5efe54f1111bba325. dead.
12. Web site: Bypassing Application Whitelisting. CERT/CC Blog . 27 July 2017.