Potential Ransomware Activity Using LegalNotice Message

testhigh
log source: windows · registry_setauthor frack113date 2022-12-11
01

description

What this is, in brief.

Detect changes to the "LegalNoticeCaption" or "LegalNoticeText" registry values where the message set contains keywords often used in ransomware ransom messages

02

tags

attack.impactattack.t1491.001
03

rule source (YAML)

title: Potential Ransomware Activity Using LegalNotice Message
id: 8b9606c9-28be-4a38-b146-0e313cc232c1
status: test
description: Detect changes to the "LegalNoticeCaption" or "LegalNoticeText" registry values where the message set contains keywords often used in ransomware ransom messages
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/5c1e6f1b4fafd01c8d1ece85f510160fc1275fbf/atomics/T1491.001/T1491.001.md
author: frack113
date: 2022-12-11
modified: 2023-08-17
tags:
    - attack.impact
    - attack.t1491.001
logsource:
    product: windows
    category: registry_set
detection:
    selection:
        TargetObject|contains:
            - '\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\LegalNoticeCaption'
            - '\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\LegalNoticeText'
        Details|contains:
            - 'encrypted'
            - 'Unlock-Password'
            - 'paying'
    condition: selection
falsepositives:
    - Unknown
level: high
simulation:
    - type: atomic-red-team
      name: Configure LegalNoticeCaption and LegalNoticeText registry keys to display ransom message
      technique: T1491.001
      atomic_guid: ffcbfaab-c9ff-470b-928c-f086b326089b
regression_tests_path: regression_data/rules/windows/registry/registry_set/registry_set_legalnotice_susp_message/info.yml
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detects techniques (1)

ATT&CK techniques this enables or maps to.

05

references

External citations — patches, advisories, analysis.