Suspicious Cobalt Strike DNS Beaconing - Sysmon — Sigma Rule

Rule metadata and linked tags

Author: Florian Roth (Nextron Systems). Source status: test; severity: critical. Source dates: 2021-11-09 / 2023-01-16.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 71ef18383ece266d2beb091974e2d32ee13463bd3745d15d5f432eee2bdc55d6

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: Suspicious Cobalt Strike DNS Beaconing - Sysmon
id: f356a9c4-effd-4608-bbf8-408afd5cd006
related:
    - id: 0d18728b-f5bf-4381-9dcf-915539fff6c2
      type: similar
status: test
description: Detects a program that invoked suspicious DNS queries known from Cobalt Strike beacons
references:
    - https://www.icebrg.io/blog/footprints-of-fin7-tracking-actor-patterns
    - https://www.sekoia.io/en/hunting-and-detecting-cobalt-strike/
author: Florian Roth (Nextron Systems)
date: 2021-11-09
modified: 2023-01-16
tags:
    - attack.command-and-control
    - attack.t1071.004
logsource:
    product: windows
    category: dns_query
detection:
    selection1:
        QueryName|startswith:
            - 'aaa.stage.'
            - 'post.1'
    selection2:
        QueryName|contains: '.stage.123456.'
    condition: 1 of selection*
falsepositives:
    - Unknown
level: critical

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://www.icebrg.io/blog/footprints-of-fin7-tracking-actor-patterns
• https://www.sekoia.io/en/hunting-and-detecting-cobalt-strike/