Detection: Windows Access Token Manipulation SeDebugPrivilege

Updated Date: 2024-09-30 ID: 6ece9ed0-5f92-4315-889d-48560472b188 Author: Teoderick Contreras, Splunk Type: Anomaly Product: Splunk Enterprise Security

Description

The following analytic detects a process enabling the "SeDebugPrivilege" privilege token. It leverages Windows Security Event Logs with EventCode 4703, filtering out common legitimate processes. This activity is significant because SeDebugPrivilege allows a process to inspect and modify the memory of other processes, potentially leading to credential dumping or code injection. If confirmed malicious, an attacker could gain extensive control over system processes, enabling them to escalate privileges, persist in the environment, or access sensitive information.

Search

1`wineventlog_security` EventCode=4703 EnabledPrivilegeList = "*SeDebugPrivilege*" AND NOT(ProcessName IN ("*\\Program File*", "*\\System32\\lsass.exe*", "*\\SysWOW64\\lsass.exe*", "*\\SysWOW64\\svchost.exe*", "*\\System32\\svchost.exe*")) 
2| stats count min(_time) as firstTime max(_time) as lastTime by Computer ProcessName ProcessId SubjectDomainName SubjectUserName SubjectUserSid TargetUserName TargetLogonId TargetDomainName EnabledPrivilegeList action 
3| `security_content_ctime(firstTime)` 
4| `security_content_ctime(lastTime)` 
5| `windows_access_token_manipulation_sedebugprivilege_filter`

Data Source

Name	Platform	Sourcetype	Source
Windows Event Log Security 4703	Windows	`'xmlwineventlog'`	`'XmlWinEventLog:Security'`

Macros Used

Name	Value
security_content_ctime	`convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)`
windows_access_token_manipulation_sedebugprivilege_filter	`search *`

windows_access_token_manipulation_sedebugprivilege_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK

+ Kill Chain Phases

+ NIST

+ CIS

- Threat Actors

ID	Technique	Tactic
T1134.002	Create Process with Token	Defense Evasion
T1134	Access Token Manipulation	Privilege Escalation

KillChainPhase.EXPLOITAITON

NistCategory.DE_AE

Cis18Value.CIS_10

Lazarus Group

Turla

Blue Mockingbird

FIN6

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting	Value
Disabled	true
Cron Schedule	`0 * * * *`
Earliest Time	`-70m@m`
Latest Time	`-10m@m`
Schedule Window	`auto`
Creates Risk Event	True

This configuration file applies to all detections of type anomaly. These detections will use Risk Based Alerting.

Implementation

To successfully implement this search, you need to be ingesting Windows Security Event Logs with 4703 EventCode enabled. The Windows TA is also required.

Known False Positives

Some native binaries and browser applications may request SeDebugPrivilege. Filter as needed.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
A process $ProcessName$ adjust its privileges with SeDebugPrivilege on $Computer$.	36	60	60

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

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`XmlWinEventLog:Security`	`XmlWinEventLog`
Integration	✅ Passing	Dataset	`XmlWinEventLog:Security`	`XmlWinEventLog`

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: GitHub | Version: 4