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Description

Detect a renamed instance of procdump.exe dumping the lsass process. This query looks for both -mm and -ma usage. -mm will produce a mini dump file and -ma will write a dump file with all process memory. Both are highly suspect and should be reviewed. Modify the query as needed.
During triage, confirm this is procdump.exe executing. If it is the first time a Sysinternals utility has been ran, it is possible there will be a -accepteula on the command line. Review other endpoint data sources for cross process (injection) into lsass.exe.

  • Type: Hunting

  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

  • Last Updated: 2021-02-01
  • Author: Michael Haag, Splunk
  • ID: 21276daa-663d-11eb-ae93-0242ac130002

Annotations

ATT&CK
ID Technique Tactic
T1003.001 LSASS Memory Credential Access
Kill Chain Phase
  • Actions on Objectives
NIST
  • DE.CM
CIS20
  • CIS 3
  • CIS 5
  • CIS 16
CVE 
1
2
3
4
5
6

`sysmon` OriginalFileName=procdump  process_name!=procdump*.exe  EventID=1 (CommandLine=*-ma* OR CommandLine=*-mm*) CommandLine=*lsass* 
| rename Computer as dest 
|  stats count min(_time) as firstTime max(_time) as lastTime by dest, parent_process_name, process_name, OriginalFileName, CommandLine 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `dump_lsass_via_procdump_rename_filter`

Macros

The SPL above uses the following Macros:

Note that dump_lsass_via_procdump_rename_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required field

  • _time
  • OriginalFileName
  • process_name
  • EventID
  • CommandLine
  • Computer
  • parent_process_name

How To Implement

To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the Endpoint datamodel in the Processes node.

Known False Positives

None identified.

Associated Analytic story

RBA

Risk Score Impact Confidence Message
80.0 80 100 The following $process_name$ has been identified as renamed, spawning from $parent_process_name$ on $dest$, attempting to dump lsass.exe.

Reference

Test Dataset

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

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