huntrule

Windows process command line matching Sliver C2 implant NoExit PowerShell UTF8 pattern

Alerts on Windows process command lines matching a Sliver-style PowerShell -NoExit encoding pattern.

FreeReviewedSigma · Critical · v2
Product
windows
Category
process_creation
Author
Nasreddine Bencherchali (Nextron Systems), Florian Roth (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2022-08-25
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 Windows process creation events where the command line contains the specific PowerShell parameter sequence: -NoExit -Command [Console]::OutputEncoding=[Text.UTF8Encoding]::UTF8. Attackers using C2 implants may spawn PowerShell with console output encoding set to UTF-8 and keep the session alive for interactive command execution. Detection relies on process_creation telemetry and matching the exact command-line substring in the executed command.

Reporting behind it

Related detections9 linkedT1059 — drag to rearrange
Suspicious OneNote Spawning Command or Script Interpreter via Spear-Phishing (via process_creation)
Malicious Web Server Process Spawning Command Interpreter via Web Shell (via process_creation)
Suspicious VMware Guest Operation Output Staging in vmware-system Temp Directory (via file_event)
Malicious Command Shell Spawned by SQL Server via Process Creation (via process_creation)
Suspicious Script Interpreter Spawned by Excel via DarkGate Lure
Suspicious AutoHotkey Script Execution from User Writable Path by DarkGate
Malicious China Chopper Web Shell Command Pattern in IIS Worker Process (via process_creation)
Malicious AutoHotKey Runner AutoNotify Executing AHKBot Looper Script (via process_creation)
Malicious IIS Worker Process Spawning Command Shell after ASP.NET ViewState Injection (via process_creation)
Windows process command line matching Sliver C2 implant NoExit PowerShell UTF8 pattern
Pivot detection · T1059 · 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.