Suspicious Outlook Child Process with Script/Macro Indicators

Jason Nelson@Jason

•updated Sep 30, 2025•10•0•272

Detects potential malicious email execution chains where Microsoft Outlook spawns suspicious child processes (e.g., powershell.exe, cmd.exe, wscript.exe, cscript.exe, mshta.exe). The rule further inspects command-line arguments and script contents for high-risk behaviors such as encoded PowerShell commands (-enc), execution of macro-enabled files (.docm, .xlsm, .js), or the presence of web download functions (DownloadFile, Invoke-WebRequest). This pattern is strongly associated with malware delivery via phishing emails, macro exploitation, and initial access techniques mapped to MITRE ATT&CK T1566 (Phishing) and T1204 (User Execution).