Detection rules › Sigma

PDF File Created By RegEdit.EXE

Status
test
Severity
high
Log source
product windows, category file_event
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.

MITRE ATT&CK coverage

TacticTechniques
StealthNo specific technique

Event coverage

ProviderEventTitle
SysmonEvent ID 11FileCreate

Rule body yaml

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

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.

FieldKindValues
Imageends_with
  • \regedit.exe corpus 8 (sigma 8)
TargetFilenameends_with
  • .pdf