Detection rules › Sigma
Renamed BrowserCore.EXE Execution
Detects process creation with a renamed BrowserCore.exe (used to extract Azure tokens)
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Stealth | |
| Credential Access |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 1: Process creation |
Rule body
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
Stages and Predicates
Stage 0: condition
selection and not 1 of filter_*Stage 1: selection
selection:
OriginalFileName: BrowserCore.exe
Stage 2: not filter_realbrowsercore
filter_realbrowsercore:
Image|endswith: '\BrowserCore.exe'
Exclusions
The rule actively suppresses these predicates.
| Field | Kind | Excluded values | Search |
|---|---|---|---|
Image | ends_with | \BrowserCore.exe | excludes:Image field:"Image" value:"\BrowserCore.exe" |
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
OriginalFileName | eq |
| field:"OriginalFileName" kind:eq value:"BrowserCore.exe" |