Detection rules › Sigma
PUA - DefenderCheck Execution
Detects the use of DefenderCheck, a tool to evaluate the signatures used in Microsoft Defender. It can be used to figure out the strings / byte chains used in Microsoft Defender to detect a tool and thus used for AV evasion.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Stealth | T1027.005 Obfuscated Files or Information: Indicator Removal from Tools |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
Rule body yaml
title: PUA - DefenderCheck Execution
id: f0ca6c24-3225-47d5-b1f5-352bf07ecfa7
status: test
description: Detects the use of DefenderCheck, a tool to evaluate the signatures used in Microsoft Defender. It can be used to figure out the strings / byte chains used in Microsoft Defender to detect a tool and thus used for AV evasion.
references:
- https://github.com/matterpreter/DefenderCheck
author: Florian Roth (Nextron Systems)
date: 2022-08-30
modified: 2023-02-04
tags:
- attack.stealth
- attack.t1027.005
logsource:
category: process_creation
product: windows
detection:
selection:
- Image|endswith: '\DefenderCheck.exe'
- Description: 'DefenderCheck'
condition: selection
falsepositives:
- Unlikely
level: high
Stages and Predicates
Stage 0: condition
selectionStage 1: selection
selection:
- Image|endswith: '\DefenderCheck.exe'
- Description: 'DefenderCheck'
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
Description | eq |
|
Image | ends_with |
|