Detection rules › Sigma

Enable LM Hash Storage

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

Detects changes to the "NoLMHash" registry value in order to allow Windows to store LM Hashes. By setting this registry value to "0" (DWORD), Windows will be allowed to store a LAN manager hash of your password in Active Directory and local SAM databases.

MITRE ATT&CK coverage

TacticTechniques
Persistence
Defense Impairment

Telemetry coverage

Rule body

title: Enable LM Hash Storage
id: c420410f-c2d8-4010-856b-dffe21866437
related:
    - id: 98dedfdd-8333-49d4-9f23-d7018cccae53 # process_creation
      type: similar
status: test
description: |
    Detects changes to the "NoLMHash" registry value in order to allow Windows to store LM Hashes.
    By setting this registry value to "0" (DWORD), Windows will be allowed to store a LAN manager hash of your password in Active Directory and local SAM databases.
references:
    - https://www.cisa.gov/news-events/cybersecurity-advisories/aa23-347a
    - https://learn.microsoft.com/en-us/troubleshoot/windows-server/windows-security/prevent-windows-store-lm-hash-password
    - https://www.sans.org/blog/protecting-privileged-domain-accounts-lm-hashes-the-good-the-bad-and-the-ugly/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-12-15
tags:
    - attack.persistence
    - attack.defense-impairment
    - attack.t1112
logsource:
    product: windows
    category: registry_set
detection:
    selection:
        TargetObject|endswith: 'System\CurrentControlSet\Control\Lsa\NoLMHash'
        Details: 'DWORD (0x00000000)'
    condition: selection
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    TargetObject|endswith: 'System\CurrentControlSet\Control\Lsa\NoLMHash'
    Details: 'DWORD (0x00000000)'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Detailseq
  • DWORD (0x00000000) corpus 38 (sigma 36, chronicle 2)
field:"Details" kind:eq value:"DWORD (0x00000000)"
TargetObjectends_with
  • System\CurrentControlSet\Control\Lsa\NoLMHash
field:"TargetObject" kind:ends_with value:"System\CurrentControlSet\Control\Lsa\NoLMHash"