Linux process discovery via common process listing and monitoring tools

Flags Linux execution of common tools used to enumerate running processes.

FreeReviewedSigma · Low · v5

Product: linux
Category: process_creation
Author: Ömer Günal, oscd.community, CheraaghiMilad (SigmaHQ), DRL 1.1
Published: 2020-10-06
Updated: 2026-07-31

ATT&CK techniques

Discovery

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
- T1057Process Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule matches Linux process creation events where the command image ends with common process discovery utilities such as atop, htop, pgrep, ps, pstree, or top. Attackers may use these tools to enumerate running processes and identify installed applications or active services for further targeting. It relies on process creation telemetry containing the executable path or image name for Linux.

Reporting behind it

Related detections9 linkedT1057 — drag to rearrange

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Windows: Recon command output piped to findstr.exe

Windows Process Execution of PCHunter (PCHunter64.exe or PCHunter32.exe)

Windows PowerShell: Suspicious Process Discovery Using Get-Process

Windows WMIC Process Flag Execution Indicating Process Reconnaissance

Linux process discovery via common process listing and monitoring tools

Pivot detection · T1057 · 9 related

Changelog

v5
Candidate ingested via manual entry.2026-07-31
v4
Candidate ingested via manual entry.2026-07-31
v3
Candidate ingested via manual entry.2026-07-31
v2
Candidate ingested via manual entry.2026-07-31
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.

linux-process-discovery-via-common-cli-enumeration-tools-4e2f5868

title: Linux process discovery via common process listing and monitoring tools
id: d4f8f898-e336-4b42-9050-67074b3258ee
status: stable
description: This rule matches Linux process creation events where the command image ends with common process discovery utilities such as atop, htop, pgrep, ps, pstree, or top. Attackers may use these tools to enumerate running processes and identify installed applications or active services for further targeting. It relies on process creation telemetry containing the executable path or image name for Linux.
references:
  - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1057/T1057.md
  - https://www.cyberciti.biz/faq/show-all-running-processes-in-linux/
  - https://github.com/SigmaHQ/sigma/blob/master/rules-threat-hunting/linux/process_creation/proc_creation_lnx_susp_running_process_discovery.yml
author: Ömer Günal, oscd.community, CheraaghiMilad, Huntrule Team
date: 2020-10-06
modified: 2022-07-07
tags:
  - attack.discovery
  - attack.t1057
  - detection.threat-hunting
logsource:
  product: linux
  category: process_creation
detection:
  selection:
    Image|endswith:
      - /atop
      - /htop
      - /pgrep
      - /ps
      - /pstree
      - /top
  condition: selection
falsepositives:
  - Legitimate administration activities
level: low
license: DRL-1.1
related:
  - id: 4e2f5868-08d4-413d-899f-dc2f1508627b
    type: derived

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