Detection rules › Splunk
Disabling Windows Local Security Authority Defences via Registry
The following analytic identifies the deletion of registry keys that disable Local Security Authority (LSA) protection and Microsoft Defender Device Guard. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on registry actions and paths associated with LSA and Device Guard settings. This activity is significant because disabling these defenses can leave a system vulnerable to various attacks, including credential theft and unauthorized code execution. If confirmed malicious, this action could allow attackers to bypass critical security mechanisms, leading to potential system compromise and persistent access.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Persistence | T1556 Modify Authentication Process |
| Defense Evasion | T1556 Modify Authentication Process |
| Credential Access | T1556 Modify Authentication Process |
Event coverage
| Provider | Event ID | Title |
|---|---|---|
| Sysmon | 13 | RegistryEvent (Value Set) |
Stages and Predicates
Stage 1: tstats
tstats WHERE ((Registry.action="modified" Registry.registry_value_data IN (0, 0x00000000)) OR Registry.action="deleted") Registry.registry_path IN ("*\\Lsa\\LsaCfgFlags", "*\\Lsa\\RunAsPPL", "*\\SOFTWARE\\Policies\\Microsoft\\Windows\\DeviceGuard\\*") 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: search
search
Stage 4: search
search
Stage 5: 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.
| Field | Kind | Values |
|---|---|---|
Registry.action | eq |
|
Registry.registry_path | in |
|
Registry.registry_value_data | in |
|