Name:Windows Access Token Manipulation Winlogon Duplicate Token Handle id:dda126d7-1d99-4f0b-b72a-4c14031f9398 version:4 date:2024-10-17 author:Teoderick Contreras, Splunk status:production type:Hunting Description:The following analytic detects a process attempting to access winlogon.exe to duplicate its handle. This is identified using Sysmon EventCode 10, focusing on processes targeting winlogon.exe with specific access rights. This activity is significant because it is a common technique used by adversaries to escalate privileges by leveraging the high privileges and security tokens associated with winlogon.exe. If confirmed malicious, this could allow an attacker to gain elevated privileges, potentially leading to full system compromise and unauthorized access to sensitive information. Data_source:
-Sysmon EventID 10
search:`sysmon` EventCode=10 TargetImage IN("*\\system32\\winlogon.exe*", "*\\SysWOW64\\winlogon.exe*") GrantedAccess = 0x1040 | stats count min(_time) as firstTime max(_time) as lastTime by SourceImage TargetImage SourceProcessGUID TargetProcessGUID SourceProcessId TargetProcessId GrantedAccess CallTrace dest user_id | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_access_token_manipulation_winlogon_duplicate_token_handle_filter`
how_to_implement: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. References: -https://docs.microsoft.com/en-us/windows/win32/api/handleapi/nf-handleapi-duplicatehandle -https://attack.mitre.org/techniques/T1134/001/ drilldown_searches:
: tags: analytic_story: - 'Brute Ratel C4' asset_type:Endpoint confidence:60 impact:60 message:A process $SourceImage$ is duplicating the handle token of winlogon.exe in $dest$ mitre_attack_id: - 'T1134.001' - 'T1134' observable: name:'dest' type:'Endpoint' - role: - 'Victim' name:'SourceImage' type:'Process Name' - role: - 'Attacker' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' required_fields: - '_time' - 'SourceImage' - 'TargetImage' - 'SourceProcessGUID' - 'TargetProcessGUID' - 'SourceProcessId' - 'TargetProcessId' - 'GrantedAccess' - 'CallTrace' - 'dest' - 'user_id' risk_score:36 security_domain:endpoint
