huntrule

Windows whoami.exe Execution With /FO CSV or Output Redirection

Detects whoami.exe runs that request CSV output or indicate output redirection for saved results.

FreeReviewedSigma · Medium · v1
Product
windows
Category
process_creation
Author
Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2023-02-28
Updated
2026-07-30
AnalysisDetection

ATT&CK techniques

Discovery

  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 process creation events where whoami.exe is executed with the /FO CSV option to format output as CSV, or where command-line patterns indicate exporting output to a file (including wildcard-style redirection such as whoami*>). Attackers commonly use whoami to enumerate the current user context before further actions, and exporting results can support staging or later collection. The detection relies on Windows process creation telemetry, specifically Image and OriginalFileName fields and CommandLine substring matches for the relevant flags and redirection patterns.

Reporting behind it

Related detections9 linkedT1033 — drag to rearrange
Suspicious Whoami Execution With Output Redirected to a File (via process_creation)
Possible Logged-On Session Discovery via Quser or Qwinsta (via process_creation)
Suspicious Reconnaissance Spawned by Injected SearchProtocolHost via process_creation
Windows Process Creation: whoami.exe Executed With /all for Full Identity Enumeration
Linux Process Execution of esxcli Network Commands for ESXi Network Discovery
Linux Process Execution of esxcli VM Listing Commands
Linux ESXi esxcli VSAN Information Discovery via esxcli Command
Linux Process Creation: ESXi esxcli system discovery via system namespace
Linux ESXi esxcli Storage Information Discovery via esxcli storage commands
Windows whoami.exe Execution With /FO CSV or Output Redirection
Pivot detection · T1033 · 9 related

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