huntrule

Windows PowerShell ScriptBlock Web Request Cmdlets and Command-Line Tools

Alerts when PowerShell script blocks reference web request and download cmdlets/commands, excluding a specific guest configuration path.

FreeReviewedSigma · Medium · v2
Product
windows
Category
ps_script
Author
James Pemberton / @4A616D6573 (SigmaHQ), DRL 1.1
Published
2019-10-24
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

Execution

  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Defense Evasion

  8. Cred Access

  9. Discovery

  10. Lateral Movement

  11. Collection

  12. C2

  13. Exfiltration

  14. Impact

What it detects

This rule flags PowerShell script block activity that invokes common web request mechanisms, including specific .NET WebRequest creation and cmdlets/aliases such as Invoke-RestMethod, Invoke-WebRequest, iwr/irm, and bits transfer commands. Attackers often use these functions to download or retrieve resources over HTTP/HTTPS or other protocols, making this activity a useful indicator of suspicious execution. It relies on PowerShell Script Block Logging telemetry containing matching command strings, with an exclusion for Guest Configuration plugin paths.

Reporting behind it

Related detections9 linkedT1059.001 — drag to rearrange
Malicious Metasploit Stager Delivery via mshta Remote HTA (via process_creation)
Suspicious PowerShell Download of Disguised Payload to ProgramData
Suspicious PowerShell WebClient Download of Executable Payload
Malicious Script Host Spawning PowerShell in Gootloader Chain
Suspicious PsExec Service Launching Encoded PowerShell Payload
Suspicious PowerShell Remote Script Execution via IEX DownloadString
Malicious SharePoint ToolShell Post-Exploitation via Encoded PowerShell (via process_creation)
Suspicious In-Memory PowerShell Execution from Web Server via Automation Assembly (via image_load)
Malicious Qilin Chrome Credential Harvesting Script Execution via IPScanner (via process_creation)
Windows PowerShell ScriptBlock Web Request Cmdlets and Command-Line Tools
Pivot detection · T1059.001 · 9 related

Changelog

v2
  1. v2
    Candidate ingested via manual entry.2026-07-31
  2. v1
    No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.