This analytic is to detect a suspicious process terminating Lsass process. Lsass process is known to be a critical process that is responsible for enforcing security policy system. This process was commonly targetted by threat actor or red teamer to gain privilege escalation or persistence in the targeted machine because it handles credentials of the logon users. In this analytic we tried to detect a suspicious process having a granted access PROCESS_TERMINATE to lsass process to modify or delete protected registrys. This technique was seen in doublezero malware that tries to wipe files and registry in compromised hosts. This anomaly detection can be a good pivot of incident response for possible credential dumping or evading security policy in a host or network environment.
- Type: Anomaly
Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Last Updated: 2022-03-28
- Author: Teoderick Contreras, Splunk
- ID: 7ab3c319-a4e7-4211-9e8c-40a049d0dba6
Kill Chain Phase
- CIS 3
- CIS 5
- CIS 16
1 2 3 4 5 6 `sysmon` EventCode=10 TargetImage=*lsass.exe GrantedAccess = 0x1 | stats count min(_time) as firstTime max(_time) as lastTime by SourceImage, TargetImage, TargetProcessId, SourceProcessId, GrantedAccess CallTrace, Computer | rename Computer as dest | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_terminating_lsass_process_filter`
The SPL above uses the following Macros:
windows_terminating_lsass_process_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
List of fields required to use this analytic.
How To Implement
This search requires Sysmon Logs and a Sysmon configuration, which includes EventCode 10 for lsass.exe. This search uses an input macro named
sysmon. We strongly recommend that you specify your environment-specific configurations (index, source, sourcetype, etc.) for Windows Sysmon logs. Replace the macro definition with configurations for your Splunk environment. The search also uses a post-filter macro designed to filter out known false positives.
Known False Positives
Associated Analytic Story
|64.0||80||80||a process $SourceImage$ terminates Lsass process in $dest$|
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
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