Detection: Windows Access Token Manipulation Winlogon Duplicate Token Handle

Updated Date: 2026-09-08 ID: dda126d7-1d99-4f0b-b72a-4c14031f9398 Author: Teoderick Contreras, Splunk Type: Hunting Product: Splunk Enterprise Security

Description

The following analytic detects a process requesting duplicate-handle and query-limited-information access to winlogon.exe. It leverages Sysmon EventCode 10 and checks for access masks that combine PROCESS_DUP_HANDLE (0x40) and PROCESS_QUERY_LIMITED_INFORMATION (0x1000).

Search

 1`sysmon`
 2EventCode=10
 3TargetImage="*:\\Windows\\system32\\winlogon.exe"
 4
 5NOT SourceImage IN (
 6    "C:\\Windows\\system32\\LogonUI.exe",
 7    "C:\\Windows\\system32\\lsass.exe",
 8    "C:\\Windows\\system32\\smss.exe",
 9    "C:\\Windows\\system32\\svchost.exe",
10    "C:\\Windows\\system32\\wbem\\wmiprvse.exe"
11)

Convert GrantedAccess from hexadecimal to decimal. 0x1040 combines PROCESS_DUP_HANDLE (0x40) and PROCESS_QUERY_LIMITED_INFORMATION (0x1000).

 1
 2| eval g_access_decimal = tonumber(replace(GrantedAccess,"0x",""),16)
 3
 4| eval PROCESS_DUP_HANDLE = 64
 5
 6| eval PROCESS_QUERY_LIMITED_INFORMATION = 4096
 7
 8| eval duplicate_handle_set = bit_and(g_access_decimal, PROCESS_DUP_HANDLE)
 9
10| eval query_limited_set = bit_and(g_access_decimal, PROCESS_QUERY_LIMITED_INFORMATION)
11
12| where duplicate_handle_set == PROCESS_DUP_HANDLE
13  AND query_limited_set == PROCESS_QUERY_LIMITED_INFORMATION
14
15
16| stats count min(_time) as firstTime
17                max(_time) as lastTime
18    BY user_id dest
19       signature_id signature granted_access Opcode
20       SourceImage SourceProcessGUID SourceProcessId
21       TargetImage TargetProcessGUID TargetProcessId
22       CallTrace vendor_product
23
24
25| eval CallTrace=split(CallTrace, "
26|")
27
28
29| `security_content_ctime(firstTime)`
30
31| `security_content_ctime(lastTime)`
32
33| `windows_access_token_manipulation_winlogon_duplicate_token_handle_filter`

Data Source

Name	Platform	Sourcetype	Source
Sysmon EventID 10	Windows	`'XmlWinEventLog'`	`'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'`

Macros Used

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

windows_access_token_manipulation_winlogon_duplicate_token_handle_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
T1134.001	Token Impersonation/Theft	Privilege Escalation

Exploitation

DE.AE

CIS 10

FIN8

VOID MANTICORE

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 Finding (Notable)	No
Creates Intermediate Finding (Risk Event)	No

Hunting detections do not generate a Finding (Notable) or Intermediate Findings (Risk Events).

Implementation

To successfully implement this search, you must be ingesting data that records process activity from your hosts to populate the endpoint data model in the processes node. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA.

Known False Positives

It is possible legitimate applications will request access to winlogon, filter as needed.

Associated Analytic Story

Brute Ratel C4

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`	`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: 10