Potential DLL Side-Loading via Microsoft Antimalware Service Executableedit

Identifies a Windows trusted program that is known to be vulnerable to DLL Search Order Hijacking starting after being renamed or from a non-standard path. This is uncommon behavior and may indicate an attempt to evade defenses via side-loading a malicious DLL within the memory space of one of those processes.

Rule type: eql

Rule indices:

  • winlogbeat-*
  • logs-endpoint.events.*
  • logs-windows.*

Severity: high

Risk score: 73

Runs every: 5 minutes

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

  • Elastic
  • Host
  • Windows
  • Threat Detection
  • Defense Evasion

Version: 1

Added (Elastic Stack release): 7.14.0

Rule authors: Elastic

Rule license: Elastic License v2

Potential false positivesedit

Microsoft Antimalware Service Executable installed on non default installation path.

Rule queryedit

process where event.type == "start" and
(process.pe.original_file_name == "MsMpEng.exe" and not process.name :
"MsMpEng.exe") or (process.name : "MsMpEng.exe" and not
process.executable : ("?:\\ProgramData\\Microsoft\\Windows
Defender\\*.exe", "?:\\Program
Files\\Windows Defender\\*.exe",
"?:\\Program Files (x86)\\Windows Defender\\*.exe"))

Threat mappingedit

Framework: MITRE ATT&CKTM