.. /Rasautou.exe

Star

Paths:

• C:\Windows\System32\rasautou.exe

Resources:

• https://github.com/fireeye/DueDLLigence
• https://www.fireeye.com/blog/threat-research/2019/10/staying-hidden-on-the-endpoint-evading-detection-with-shellcode.html

Acknowledgements:

• FireEye (@FireEye)

Detections:

• Sigma: https://github.com/SigmaHQ/sigma/blob/08ca62cc8860f4660e945805d0dd615ce75258c1/rules/windows/process_creation/win_rasautou_dll_execution.yml
• IOC: rasautou.exe command line containing -d and -p

Execute

1. Loads the target .DLL specified in -d and executes the export specified in -p. Options removed in Windows 10.

   rasautou -d powershell.dll -p powershell -a a -e e

   Use case

   Execute DLL code

   Privileges required

   User, Administrator in Windows 8

   Operating systems

   Windows vista, Windows 7, Windows 8, Windows 8.1

   ATT&CK® technique

   T1218

   Tags

   Execute: DLL

   This LOLBAS executes Dynamic-Link Libraries (DLLs).