Proxy Execution via Appcert (PowerShell)

id: '32821.58286'
title: Proxy Execution via Appcert
description: Threat actors may exploit legitimate developer utilities to execute malicious
  payloads by proxy. One such utility is appcert.exe, a command-line tool included
  in the Windows Application Certification Kit, which is typically used to verify
  the compliance of Windows applications with Microsoft's certification standards.
  This use case detects appcert executions with commands to proxy execution of another
  binary. Living Off the Land Binary and Scripts (LOLBAS) (LOLBIN)
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_powershell` (TERM(EventCode=4103) OR
  "<EventID>4103<" OR TERM(EventCode=4104) OR "<EventID>4104<") (TERM(appcert) OR
  "appcert.exe") TERM(test) | regex process!="(?i)\-setupcommandline"| regex process="(?i)\stest\s"|
  rex field=process "-setuppath\s+(?:\"|'')?(?<proxy_exec>[^\s\"'']+\.exe)(?:\"|'')?"
  | table _time, host, user, process, proxy_exec | bin span=1s | stats values(*) as
  * by _time, host '
techniques:
- defense-evasion:trusted developer utilities proxy execution
technique_id: 
- T1127
data_category:
- PowerShell logs
references:
- https://attack.mitre.org/techniques/T1127/
- https://attack.mitre.org/techniques/T1218/007/
- https://lolbas-project.github.io/lolbas/OtherMSBinaries/Appcert/