Try in Splunk Security Cloud

Description

This search detects loading of unsigned images by LSASS. Deprecated because too noisy.

  • Type: TTP

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

  • Last Updated: 2019-12-06
  • Author: Patrick Bareiss, Splunk
  • ID: 56ef054c-76ef-45f9-af4a-a634695dcd65

Annotations

ATT&CK
ID Technique Tactic
T1003.001 LSASS Memory Credential Access
Kill Chain Phase
  • Actions on Objectives
NIST
  • DE.CM
CIS20
  • CIS 8
  • CIS 16
CVE 
1
2
3
4
5
6

`sysmon` EventID=7 Image=*lsass.exe Signed=false 
| stats count min(_time) as firstTime max(_time) as lastTime by Computer, Image, ImageLoaded, Signed, SHA1 
| rename Computer as dest 
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)` 
| `unsigned_image_loaded_by_lsass_filter`

Macros

The SPL above uses the following Macros:

Note that unsigned_image_loaded_by_lsass_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

How To Implement

This search needs Sysmon Logs with a sysmon configuration, which includes EventCode 7 with 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

Other tools could load images into LSASS for legitimate reason. But enterprise tools should always use signed DLLs.

Associated Analytic story

RBA

Risk Score Impact Confidence Message
25.0 50 50 tbd

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

source | version: 1