Credential Dumping via Symlink to Shadow Copy

Original Source: [splunk source]
Name:Credential Dumping via Symlink to Shadow Copy
id:c5eac648-fae0-4263-91a6-773df1f4c903
version:5
date:2024-11-28
author:Patrick Bareiss, Splunk
status:production
type:TTP
Description:The following analytic detects the creation of a symlink to a shadow copy, which may indicate credential dumping attempts. It leverages the Endpoint.Processes data model in Splunk to identify processes executing commands containing "mklink" and "HarddiskVolumeShadowCopy". This activity is significant because attackers often use this technique to manipulate or delete shadow copies, hindering system backup and recovery efforts. If confirmed malicious, this could prevent data restoration, complicate incident response, and lead to data loss or compromise. Analysts should review the process details, user, parent process, and any related artifacts to identify the attack source.
Data_source:
  • -Sysmon EventID 1
  • -Windows Event Log Security 4688
  • -CrowdStrike ProcessRollup2
search:| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_cmd` Processes.process=*mklink* Processes.process=*HarddiskVolumeShadowCopy* by Processes.dest Processes.user Processes.process_name Processes.process Processes.parent_process Processes.parent_process_name Processes.original_file_name Processes.process_id Processes.parent_process_id
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`| `security_content_ctime(lastTime)`
| `credential_dumping_via_symlink_to_shadow_copy_filter`


how_to_implement:The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint` data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
known_false_positives:unknown
References:
  -https://2017.zeronights.org/wp-content/uploads/materials/ZN17_Kheirkhabarov_Hunting_for_Credentials_Dumping_in_Windows_Environment.pdf
drilldown_searches:
name:'View the detection results for - "$user$" and "$dest$"'
search:'%original_detection_search% | search user = "$user$" dest = "$dest$"'
earliest_offset:'$info_min_time$'
latest_offset:'$info_max_time$'
name:'View risk events for the last 7 days for - "$user$" and "$dest$"'
search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$", "$dest$") starthoursago=168 | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
earliest_offset:'$info_min_time$'
latest_offset:'$info_max_time$'
tags:
  analytic_story:
    - 'Compromised Windows Host'
    - 'Credential Dumping'
  asset_type:Endpoint
  confidence:90
  impact:90
  message:An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ by user $user$ attempting to create symlink to a shadow copy to grab credentials.
  mitre_attack_id:
    - 'T1003.003'
    - 'T1003'
  observable:
    name:'user'
    type:'User'
    - role:
      - 'Victim'
    name:'dest'
    type:'Hostname'
    - role:
      - 'Victim'
  product:
    - 'Splunk Enterprise'
    - 'Splunk Enterprise Security'
    - 'Splunk Cloud'
  required_fields:
    - '_time'
    - 'Processes.dest'
    - 'Processes.user'
    - 'Processes.parent_process_name'
    - 'Processes.parent_process'
    - 'Processes.original_file_name'
    - 'Processes.process_name'
    - 'Processes.process'
    - 'Processes.process_id'
    - 'Processes.parent_process_path'
    - 'Processes.process_path'
    - 'Processes.parent_process_id'
  risk_score:81
  security_domain:endpoint

tests:
name:'True Positive Test'
 attack_data:
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1003.003/atomic_red_team/windows-sysmon.log
  source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
  sourcetype: XmlWinEventLog
manual_test:None