Detection rules › Splunk

Windows LSA Secrets NoLMhash Registry

Author
Teoderick Contreras, Splunk
Source
upstream

The following analytic detects modifications to the Windows registry related to the Local Security Authority (LSA) NoLMHash setting. It identifies when the registry value is set to 0, indicating that the system will store passwords in the weaker Lan Manager (LM) hash format. This detection leverages registry activity logs from endpoint data sources like Sysmon or EDR tools. Monitoring this activity is crucial as it can indicate attempts to weaken password storage security. If confirmed malicious, this could allow attackers to exploit weaker LM hashes, potentially leading to unauthorized access and credential theft.

MITRE ATT&CK coverage

TacticTechniques
Credential AccessT1003.004 OS Credential Dumping: LSA Secrets

Event coverage

ProviderEvent IDTitle
Sysmon13RegistryEvent (Value Set)

Stages and Predicates

Stage 1: tstats

tstats WHERE Registry.registry_path="*\\System\\CurrentControlSet\\Control\\Lsa\\NoLMHash" Registry.registry_value_data=0x00000000 BY Registry.action, Registry.dest, Registry.process_guid, Registry.process_id, Registry.registry_hive, Registry.registry_path, Registry.registry_key_name, Registry.registry_value_data, Registry.registry_value_name, Registry.registry_value_type, Registry.status, Registry.user, Registry.vendor_product

Stage 2: search

search

Stage 3: where

where isnotnull(registry_value_data)

Stage 4: search

search

Stage 5: search

search

Stage 6: search

search `macro`

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
Registry.registry_patheq
  • "*\\System\\CurrentControlSet\\Control\\Lsa\\NoLMHash"
Registry.registry_value_dataeq
  • 0x00000000 corpus 8 (splunk 8)