Wfc.exe

Commands

1. AWL BypassUser T1127

   Execute proxied payload with Microsoft signed binary to bypass WDAC policies

   wfc.exe {PATH_ABSOLUTE:.xoml}

   Execute arbitrary C# code embedded in a XOML file.

   os: Windows 10 2004 (likely previous and newer versions as well)

   Execute: XOML

Detection

• BlockRule https://docs.microsoft.com/en-us/windows/security/threat-protection/windows-defender-application-control/microsoft-recommended-block-rules
• Sigma https://github.com/SigmaHQ/sigma/blob/6b34764215b0e97e32cbc4c6325fc933d2695c3a/rules/windows/process_creation/proc_creation_win_lolbin_wfc.yml
• IOCAs a Windows SDK binary, execution on a system may be suspicious

Code samples

• https://bohops.com/2020/11/02/exploring-the-wdac-microsoft-recommended-block-rules-part-ii-wfc-fsi/

Resources

• https://bohops.com/2020/11/02/exploring-the-wdac-microsoft-recommended-block-rules-part-ii-wfc-fsi/