Detection rules › Splunk

Windows Remote Services Allow Remote Assistance

Author
Teoderick Contreras, Splunk
Source
upstream

The following analytic detects modifications in the Windows registry to enable remote desktop assistance on a targeted machine. It leverages data from the Endpoint.Registry datamodel, specifically monitoring changes to the "Control\Terminal Server\fAllowToGetHelp" registry path. This activity is significant because enabling remote assistance via registry is uncommon and often associated with adversaries or malware like Azorult. If confirmed malicious, this could allow an attacker to remotely access and control the compromised host, leading to potential data exfiltration or further system compromise.

MITRE ATT&CK coverage

TacticTechniques
Lateral MovementT1021.001 Remote Services: Remote Desktop Protocol

Event coverage

ProviderEvent IDTitle
Sysmon13RegistryEvent (Value Set)

Stages and Predicates

Stage 1: tstats

tstats WHERE Registry.registry_path="*\\Control\\Terminal Server\\fAllowToGetHelp*" Registry.registry_value_data="0x00000001" 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_patheq
  • "*\\Control\\Terminal Server\\fAllowToGetHelp*"
Registry.registry_value_dataeq
  • "0x00000001" corpus 42 (splunk 42)