PUA - CsExec Execution — Sigma Rule

Rule metadata and linked tags

Author: Florian Roth (Nextron Systems). Source status: test; severity: high. Source dates: 2022-08-22 / 2023-02-21.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 1f008989e574197712cce0b43493d1dd5391d84809a2cdc5943bc703d0df6b0e

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: PUA - CsExec Execution
id: d08a2711-ee8b-4323-bdec-b7d85e892b31
status: test
description: Detects the use of the lesser known remote execution tool named CsExec a PsExec alternative
references:
    - https://github.com/malcomvetter/CSExec
    - https://www.microsoft.com/security/blog/2022/05/09/ransomware-as-a-service-understanding-the-cybercrime-gig-economy-and-how-to-protect-yourself/
author: Florian Roth (Nextron Systems)
date: 2022-08-22
modified: 2023-02-21
tags:
    - attack.resource-development
    - attack.t1587.001
    - attack.execution
    - attack.t1569.002
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\csexec.exe'
    selection_pe:
        Description: 'csexec'
    condition: 1 of selection*
falsepositives:
    - Unknown
level: high

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://github.com/malcomvetter/CSExec
• https://www.microsoft.com/security/blog/2022/05/09/ransomware-as-a-service-understanding-the-cybercrime-gig-economy-and-how-to-protect-yourself/