Windows Private Keys Discovery

Original Source: [splunk source]
Name:Windows Private Keys Discovery
id:5c1c2877-06c0-40ee-a1a2-db71f1372b5b
version:3
date:2024-09-30
author:Teoderick Contreras, Splunk
status:production
type:Anomaly
Description:The following analytic identifies processes that retrieve information related to private key files, often used by post-exploitation tools like winpeas. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions that search for private key certificates. This activity is significant as it indicates potential attempts to locate insecurely stored credentials, which adversaries can exploit for privilege escalation, persistence, or remote service authentication. If confirmed malicious, this behavior could allow attackers to access sensitive information, escalate privileges, or maintain persistence within the compromised environment.
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 Processes.process = "*dir *" OR Processes.process = "*findstr*" AND Processes.process IN ( "*.rdg*", "*.gpg*", "*.pgp*", "*.p12*", "*.der*", "*.csr*", "*.cer*", "*.ovpn*", "*.key*", "*.ppk*", "*.p12*", "*.pem*", "*.pfx*", "*.p7b*", "*.asc*") by Processes.process_name Processes.original_file_name Processes.process Processes.process_id Processes.process_guid Processes.parent_process_name Processes.parent_process Processes.parent_process_guid Processes.dest Processes.user
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_private_keys_discovery_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://attack.mitre.org/techniques/T1552/004/
  -https://github.com/carlospolop/PEASS-ng/tree/master/winPEAS
  -https://www.microsoft.com/en-us/security/blog/2022/10/14/new-prestige-ransomware-impacts-organizations-in-ukraine-and-poland/
drilldown_searches:
name:'View the detection results for - "$dest$"'
search:'%original_detection_search% | search dest = "$dest$"'
earliest_offset:'$info_min_time$'
latest_offset:'$info_max_time$'
name:'View risk events for the last 7 days for - "$dest$"'
search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") 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:
    - 'Windows Post-Exploitation'
    - 'Prestige Ransomware'
  asset_type:Endpoint
  confidence:50
  impact:50
  message:a process with commandline $process$ that can retrieve information related to private keys in $dest$
  mitre_attack_id:
    - 'T1552.004'
    - 'T1552'
  observable:
    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'
    - 'Processes.parent_process_guid'
    - 'Processes.process_guid'
  risk_score:25
  security_domain:endpoint

tests:
name:'True Positive Test'
 attack_data:
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/malware/winpeas/winpeas_search_private_key/dir-private-sysmon.log
  source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
  sourcetype: XmlWinEventLog
  update_timestamp: True
manual_test:None