Try in Splunk Security Cloud

Description

The following analytic identifies a modification in the Windows registry related to authentication level settings. This registry is the configuration for authentication level settings within the Terminal Server Client settings in Windows. AuthenticationLevelOverride might be used to control or override the authentication level used by the Terminal Server Client for remote connections. DarkGate malware modify this registry as part of its malicious installation in a targeted host for its remote desktop capabilities.

  • Type: Anomaly
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Authentication, Endpoint
  • Last Updated: 2023-11-23
  • Author: Teoderick Contreras, Splunk
  • ID: 6410a403-36bb-490f-a06a-11c3be7d2a41

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1112 Modify Registry Defense Evasion
Kill Chain Phase
  • Exploitation
NIST
  • DE.AE
CIS20
  • CIS 10
CVE 


1
2
3
4
5
6



| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Registry where Registry.registry_path = "*\\Terminal Server Client\\AuthenticationLevelOverride"  Registry.registry_value_data = 0x00000000 by  Registry.registry_path Registry.registry_value_name Registry.registry_value_data Registry.process_guid Registry.action Registry.user Registry.dest 
| `drop_dm_object_name(Registry)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_modify_registry_authenticationleveloverride_filter`

Macros

The SPL above uses the following Macros:

:information_source: windows_modify_registry_authenticationleveloverride_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • Registry.registry_key_name
  • Registry.registry_path
  • Registry.user
  • Registry.dest
  • Registry.registry_value_name
  • Registry.action

How To Implement

To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the Endpoint datamodel in the Registry node. Also make sure that this registry was included in your config files ex. sysmon config to be monitored.

Known False Positives

Administrators may enable or disable this feature that may cause some false positive, however is not common. Filter as needed.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
49.0 70 70 the registry for authentication level settings was modified on $dest$.

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

source | version: 1