Allow RDP Remote Assistance Feature

Hunt Hypothesis

Detect enable rdp feature to allow specific user to rdp connect on the targeted machine

Detection Rule

Sigma (Original)

title: Allow RDP Remote Assistance Feature
id: 37b437cf-3fc5-4c8e-9c94-1d7c9aff842b
status: test
description: Detect enable rdp feature to allow specific user to rdp connect on the targeted machine
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/40b77d63808dd4f4eafb83949805636735a1fd15/atomics/T1112/T1112.md
author: frack113
date: 2022-08-19
modified: 2023-08-17
tags:
    - attack.persistence
    - attack.defense-impairment
    - attack.t1112
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject|endswith: 'System\CurrentControlSet\Control\Terminal Server\fAllowToGetHelp'
        Details: DWORD (0x00000001)
    condition: selection
falsepositives:
    - Legitimate use of the feature (alerts should be investigated either way)
level: medium
regression_tests_path: regression_data/rules/windows/registry/registry_set/registry_set_allow_rdp_remote_assistance_feature/info.yml
simulation:
    - type: atomic-red-team
      name: Allow RDP Remote Assistance Feature
      technique: T1112
      atomic_guid: 86677d0e-0b5e-4a2b-b302-454175f9aa9e

KQL (Azure Sentinel)

imRegistry
| where RegistryKey endswith "System\\CurrentControlSet\\Control\\Terminal Server\\fAllowToGetHelp" and RegistryValueData =~ "DWORD (0x00000001)"

KQL (Microsoft 365 Defender)

DeviceRegistryEvents
| where RegistryKey endswith "System\\CurrentControlSet\\Control\\Terminal Server\\fAllowToGetHelp" and RegistryValueData =~ "DWORD (0x00000001)"

Required Data Sources

False Positive Guidance

• Legitimate use of the feature (alerts should be investigated either way)

MITRE ATT&CK Context

• Tactic: Persistence
• Technique: T1112 — T1112

References

• https://github.com/redcanaryco/atomic-red-team/blob/40b77d63808dd4f4eafb83949805636735a1fd15/atomics/T1112/T1112.md
• SigmaHQ Rule