HackTool - CobaltStrike BOF Injection Pattern — Sigma Rule

Rule metadata and linked tags

Author: Christian Burkard (Nextron Systems). Source status: test; severity: high. Source dates: 2021-08-04 / 2023-11-28.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: d18552cbc407cbba645c369f88a58e3ee6f4bc33c959d530047736b426e229b2

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: HackTool - CobaltStrike BOF Injection Pattern
id: 09706624-b7f6-455d-9d02-adee024cee1d
status: test
description: Detects a typical pattern of a CobaltStrike BOF which inject into other processes
references:
    - https://github.com/boku7/injectAmsiBypass
    - https://github.com/boku7/spawn
author: Christian Burkard (Nextron Systems)
date: 2021-08-04
modified: 2023-11-28
tags:
    - attack.execution
    - attack.defense-impairment
    - attack.t1106
    - attack.t1685
logsource:
    category: process_access
    product: windows
detection:
    selection:
        CallTrace|re: '^C:\\Windows\\SYSTEM32\\ntdll\.dll\+[a-z0-9]{4,6}\|C:\\Windows\\System32\\KERNELBASE\.dll\+[a-z0-9]{4,6}\|UNKNOWN\([A-Z0-9]{16}\)$'
        GrantedAccess:
            - '0x1028'
            - '0x1fffff'
    condition: selection
falsepositives:
    - Unknown
level: high

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://github.com/boku7/injectAmsiBypass
• https://github.com/boku7/spawn