Detection rules › Splunk

Logon Script Event Trigger Execution

Author
Teoderick Contreras, Splunk
Source
upstream

The following analytic detects the modification of the UserInitMprLogonScript registry entry, which is often used by attackers to establish persistence and gain privilege escalation upon system boot. It leverages data from the Endpoint.Registry data model, focusing on changes to the specified registry path. This activity is significant because it is a common technique used by APT groups and malware to ensure their payloads execute automatically when the system starts. If confirmed malicious, this could allow attackers to maintain persistent access and potentially escalate their privileges on the compromised host.

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1037.001 Boot or Logon Initialization Scripts: Logon Script (Windows)
Privilege EscalationT1037.001 Boot or Logon Initialization Scripts: Logon Script (Windows)

Event coverage

ProviderEvent IDTitle
Sysmon13RegistryEvent (Value Set)

Stages and Predicates

Stage 1: tstats

tstats WHERE Registry.registry_path="*\\Environment\\UserInitMprLogonScript" 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.

FieldKindValues
Registry.registry_pathin
  • "*\\Environment\\UserInitMprLogonScript"