Cobalt Strike DNS Beaconing — Sigma Rule

Rule metadata and linked tags

Author: Florian Roth (Nextron Systems). Source status: test; severity: critical. Source dates: 2018-05-10 / 2022-10-09.

{
  "category": "dns"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 427596be2627bf4bd69fa9fe10716aa5890745861a68be350eb0624a45d1d8da

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: Cobalt Strike DNS Beaconing
id: 2975af79-28c4-4d2f-a951-9095f229df29
status: test
description: Detects 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: 2018-05-10
modified: 2022-10-09
tags:
    - attack.command-and-control
    - attack.t1071.004
logsource:
    category: dns
detection:
    selection1:
        query|startswith:
            - 'aaa.stage.'
            - 'post.1'
    selection2:
        query|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/