Windows Defender Antivirus Spawning Suspicious Child Processes (Windows Defender 0-day Vulnerability)

This rule detects instances where the Windows Defender Antivirus service (MsMpEng.exe) spawns common command-line shells (cmd.exe, powershell.exe, conhost.exe) while running under the SYSTEM context. This behavior is highly irregular for a security product and is indicative of process injection, exploit payload execution, or anti-tampering bypass attempts.