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WhoAmI as Parameter — Sigma Rule

Sigma rule e9142d84-fbe0-401d-ac50-3e519fb00c89. WhoAmI as Parameter — Sigma Rule. Detects a suspicious process command line that uses whoami as first parameter (as e.g. used by EfsPotato)

Rule metadata and linked tags

Author: Florian Roth (Nextron Systems). Source status: test; severity: high. Source dates: 2021-11-29 / 2022-12-25.

{
  "category": "process_creation",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: f1a2ec7ccf346470771611b7e2fd9fc142c4b2082ae3f4e36a4e968ddf5c03ea

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: WhoAmI as Parameter
id: e9142d84-fbe0-401d-ac50-3e519fb00c89
status: test
description: Detects a suspicious process command line that uses whoami as first parameter (as e.g. used by EfsPotato)
references:
    - https://twitter.com/blackarrowsec/status/1463805700602224645?s=12
author: Florian Roth (Nextron Systems)
date: 2021-11-29
modified: 2022-12-25
tags:
    - attack.discovery
    - attack.t1033
    - car.2016-03-001
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        CommandLine|contains: '.exe whoami'
    condition: selection
falsepositives:
    - Unknown
level: high

Original YAML and metadata in JSON

False positives

  • Unknown

Source references

Connected ecosystem references

Exact source-tagged techniques

Telemetry review

Read the original logsource above, then inspect the linked detection workspaces for technique-level sensor context. No per-rule telemetry equivalence is inferred.

Pinned research references. No browser attack runner, live simulation result or validated detector is asserted. Source mappings and validation limits are preserved. ATT&CK / Atomic provenance · Detection provenance.