3CXDesktopApp.exe Execution (Windows Event Log)

id: '17332.28227'
title: 3CXDesktopApp.exe Execution
description: 'Malicious activity has been detected on March 29, 2023, originating
  from a legitimate and signed binary called 3CXDesktopApp, which is a softphone application
  from 3CX. This malicious activity includes beaconing to infrastructure controlled
  by the attackers, deployment of additional payloads in the second stage, and in
  a few cases, direct interaction by the attackers with the system. - Campaign: SmoothOperator
  - Threat Actor Association: Lazarus Group (aka Labyrinth Chollima)'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR
  "<EventID>4688<" OR Type=Process) ("3CXDesktopApp.exe" OR "3CX Desktop App") | table
  _time, host, user process, process_*, signature_id, parent_* | bin span=1s | stats
  values(*) as * by _time, host '
techniques:
- defense-evasion:system binary proxy execution
- initial-access:supply chain compromise
- execution:user execution:malicious file
technique_id:
- T1218
- T1195
- T1204.002
data_category:
- Windows event logs
references:
- https://www.crowdstrike.com/blog/crowdstrike-detects-and-prevents-active-intrusion-campaign-targeting-3cxdesktopapp-customers/
- https://www.sentinelone.com/blog/smoothoperator-ongoing-campaign-trojanizes-3cx-software-in-software-supply-chain-attack/
- https://news.sophos.com/en-us/2023/03/29/3cx-dll-sideloading-attack/