Renamed BrowserCore.EXE Execution — Sigma Rule

Rule metadata and linked tags

Author: Max Altgelt (Nextron Systems). Source status: test; severity: high. Source dates: 2022-06-02 / 2023-02-03.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: c1db5b01fc067d3f74f2ba83516fbc9a89428b5c37ce43a99b5f65aa82829a84

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: Renamed BrowserCore.EXE Execution
id: 8a4519e8-e64a-40b6-ae85-ba8ad2177559
status: test
description: Detects process creation with a renamed BrowserCore.exe (used to extract Azure tokens)
references:
    - https://twitter.com/mariuszbit/status/1531631015139102720
author: Max Altgelt (Nextron Systems)
date: 2022-06-02
modified: 2023-02-03
tags:
    - attack.credential-access
    - attack.stealth
    - attack.t1528
    - attack.t1036.003
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        OriginalFileName: BrowserCore.exe
    filter_realbrowsercore:
        Image|endswith: '\BrowserCore.exe'
    condition: selection and not 1 of filter_*
falsepositives:
    - Unknown
level: high

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://twitter.com/mariuszbit/status/1531631015139102720