PDF File Created By RegEdit.EXE

Status: test
Severity: high
Log source: category file_event, product windows
Author: Nasreddine Bencherchali (Nextron Systems)
Source: github.com/SigmaHQ/sigma

Detects the creation of a file with the ".pdf" extension by the "RegEdit.exe" process. This indicates that a user is trying to print/save a registry key as a PDF in order to potentially extract sensitive information and bypass defenses.

Known false positives

Unlikely

MITRE ATT&CK coverage

Tactic	Techniques
Stealth	No specific technique

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 11: FileCreate

Rule body

title: PDF File Created By RegEdit.EXE
id: 145095eb-e273-443b-83d0-f9b519b7867b
status: test
description: |
    Detects the creation of a file with the ".pdf" extension by the "RegEdit.exe" process.
    This indicates that a user is trying to print/save a registry key as a PDF in order to potentially extract sensitive information and bypass defenses.
references:
    - https://sensepost.com/blog/2024/dumping-lsa-secrets-a-story-about-task-decorrelation/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2024-07-08
tags:
    - attack.stealth
logsource:
    category: file_event
    product: windows
detection:
    selection:
        Image|endswith: '\regedit.exe'
        TargetFilename|endswith: '.pdf'
    condition: selection
falsepositives:
    - Unlikely
level: high

Stages and Predicates

Stage 0: `condition`

selection

Stage 1: `selection`

selection:
    Image|endswith: '\regedit.exe'
    TargetFilename|endswith: '.pdf'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`Image`	ends_with	`\regedit.exe` corpus 8 (sigma 8)	`field:"Image" kind:ends_with value:"\regedit.exe"`
`TargetFilename`	ends_with	`.pdf`	`field:"TargetFilename" kind:ends_with value:".pdf"`