Detect the hands on keyboard behavior of Windows Task Manager creating a process dump of lsass.exe. Upon this behavior occurring, a file write/modification will occur in the users profile under \AppData\Local\Temp. The dump file, lsass.dmp, cannot be renamed, however if the dump occurs more than once, it will be named lsass (2).dmp.
- Type: TTP
Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Last Updated: 2020-02-03
- Author: Michael Haag, Splunk
- ID: b2fbe95a-9c62-4c12-8a29-24b97e84c0cd
Kill Chain Phase
- Actions on Objectives
- CIS 6
- CIS 8
1 2 3 4 5 6 `sysmon` EventID=11 process_name=taskmgr.exe TargetFilename=*lsass*.dmp | stats count min(_time) as firstTime max(_time) as lastTime by Computer, object_category, process_name, TargetFilename | rename Computer as dest | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `creation_of_lsass_dump_with_taskmgr_filter`
The SPL above uses the following Macros:
creation_of_lsass_dump_with_taskmgr_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 11 for detecting file create of lsass.dmp. 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
Administrators can create memory dumps for debugging purposes, but memory dumps of the LSASS process would be unusual.
Associated Analytic Story
|80.0||80||100||$process_name$ was identified on endpoint $Computer$ writing $TargetFilename$ to disk. This behavior is related to dumping credentials via Task Manager.|
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
source | version: 1