.. /At.exe
Star

Execute

Schedule periodic tasks

Paths:

C:\WINDOWS\System32\At.exe
C:\WINDOWS\SysWOW64\At.exe

Resources:

Acknowledgements:

Freddie Barr-Smith
Riccardo Spolaor
Mariano Graziano
Xabier Ugarte-Pedrero

Detection:

Sigma: https://github.com/SigmaHQ/sigma/blob/62d4fd26b05f4d81973e7c8e80d7c1a0c6a29d0e/rules/windows/process_creation/proc_creation_win_at_interactive_execution.yml
Sigma: https://github.com/SigmaHQ/sigma/blob/62d4fd26b05f4d81973e7c8e80d7c1a0c6a29d0e/rules/network/zeek/zeek_smb_converted_win_atsvc_task.yml
Sigma: https://github.com/SigmaHQ/sigma/blob/62d4fd26b05f4d81973e7c8e80d7c1a0c6a29d0e/rules/windows/builtin/security/win_security_atsvc_task.yml
IOC: C:\Windows\System32\Tasks\At1 (substitute 1 with subsequent number of at job)
IOC: C:\Windows\Tasks\At1.job
IOC: Registry Key - Microsoft\Windows NT\CurrentVersion\Schedule\TaskCache\Tree\At1.

Execute

Create a recurring task to execute every day at a specific time.

C:\Windows\System32\at.exe 09:00 /interactive /every:m,t,w,th,f,s,su C:\Windows\System32\revshell.exe

Usecase: Create a recurring task, to eg. to keep reverse shell session(s) alive
Privileges required: Local Admin
OS: Windows 7 or older
MITRE ATT&CK®: T1053.002