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Description

The following analytic identifies the use of reg.exe attempting to export Windows registry keys that contain hashed credentials. Adversaries will utilize this technique to capture and perform offline password cracking.

  • Type: TTP
  • Product: Splunk Behavioral Analytics
  • Datamodel: Endpoint_Processes
  • Last Updated: 2021-11-29
  • Author: Jose Hernandez, Splunk
  • ID: 14038953-e5f2-4daf-acff-5452062baf03

ATT&CK

ID Technique Tactic
T1003 OS Credential Dumping Credential Access
T1003.002 Security Account Manager Credential Access 
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| from read_ssa_enriched_events() 
| eval timestamp=parse_long(ucast(map_get(input_event, "_time"), "string", null)) 
| eval process_name=lower(ucast(map_get(input_event, "process_name"), "string", null)), cmd_line=ucast(map_get(input_event, "process"), "string", null), dest_user_id=ucast(map_get(input_event, "dest_user_id"), "string", null), dest_device_id=ucast(map_get(input_event, "dest_device_id"), "string", null), event_id=ucast(map_get(input_event, "event_id"), "string", null) 
| where process_name="cmd.exe" OR process_name="reg.exe" 
| where cmd_line != null  AND match_regex(cmd_line, /(?i)save\s+/)=true AND ( match_regex(cmd_line, /(?i)HKLM\\Security/)=true OR match_regex(cmd_line, /(?i)HKLM\\SAM/)=true OR match_regex(cmd_line, /(?i)HKLM\\System/)=true OR match_regex(cmd_line, /(?i)HKEY_LOCAL_MACHINE\\Security/)=true OR match_regex(cmd_line, /(?i)HKEY_LOCAL_MACHINE\\SAM/)=true OR match_regex(cmd_line, /(?i)HKEY_LOCAL_MACHINE\\System/)=true ) 
| eval start_time = timestamp, end_time = timestamp, entities = mvappend(dest_device_id, dest_user_id), body=create_map(["event_id", event_id, "cmd_line", cmd_line, "process_name", process_name]) 
| into write_ssa_detected_events();

Macros

The SPL above uses the following Macros:

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

Required field

  • process_name
  • _time
  • dest_device_id
  • dest_user_id
  • process
  • cmd_line

How To Implement

To successfully implement this search, you need to be ingesting logs with the process name, parent process, and command-line executions from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA.

Known False Positives

None identified.

Associated Analytic story

Kill Chain Phase

  • Actions on Objectives

RBA

Risk Score Impact Confidence Message
63.0 70 90 An attempt to save registry keys storing credentials has been performed on $dest_device_id$ by $dest_user_id$ via process $process_name$.

Note that risk score is calculated base on the following formula: (Impact * Confidence)/100

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: 2