Creation or Modification of Domain Backup DPAPI private key
editCreation or Modification of Domain Backup DPAPI private key
editIdentifies the creation or modification of Domain Backup private keys. Adversaries may extract the Data Protection API (DPAPI) domain backup key from a Domain Controller (DC) to be able to decrypt any domain user master key file.
Rule type: eql
Rule indices:
- winlogbeat-*
- logs-endpoint.events.*
- logs-windows.sysmon_operational-*
- endgame-*
Severity: high
Risk score: 73
Runs every: 5m
Searches indices from: now-9m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References:
Tags:
- Domain: Endpoint
- OS: Windows
- Use Case: Threat Detection
- Tactic: Credential Access
- Data Source: Elastic Endgame
- Data Source: Elastic Defend
- Data Source: Sysmon
Version: 107
Rule authors:
- Elastic
Rule license: Elastic License v2
Investigation guide
editTriage and analysis
Domain DPAPI Backup keys are stored on domain controllers and can be dumped remotely with tools such as Mimikatz. The resulting .pvk private key can be used to decrypt ANY domain user masterkeys, which then can be used to decrypt any secrets protected by those keys.
Setup
editSetup
If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2,
events will not define event.ingested and default fallback for EQL rules was not added until version 8.2.
Hence for this rule to work effectively, users will need to add a custom ingest pipeline to populate
event.ingested to @timestamp.
For more details on adding a custom ingest pipeline refer - https://www.elastic.co/guide/en/fleet/current/data-streams-pipeline-tutorial.html
Rule query
editfile where host.os.type == "windows" and event.type != "deletion" and file.name : ("ntds_capi_*.pfx", "ntds_capi_*.pvk")
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Credential Access
- ID: TA0006
- Reference URL: https://attack.mitre.org/tactics/TA0006/
-
Technique:
- Name: Unsecured Credentials
- ID: T1552
- Reference URL: https://attack.mitre.org/techniques/T1552/
-
Sub-technique:
- Name: Private Keys
- ID: T1552.004
- Reference URL: https://attack.mitre.org/techniques/T1552/004/
-
Technique:
- Name: Credentials from Password Stores
- ID: T1555
- Reference URL: https://attack.mitre.org/techniques/T1555/