FirstTime Seen Account Performing DCSync

Elastic Stack Serverless Security

This rule identifies when a User Account starts the Active Directory Replication Process for the first time. Attackers can use the DCSync technique to get credential information of individual accounts or the entire domain, thus compromising the entire domain.

Rule type: new_terms

Rule indices:

• winlogbeat-*
• logs-system.*
• logs-windows.*

Severity: high

Risk score: 73

Runs every: 5m

Searches indices from: now-9m (https://www.elastic.co/guide/en/elasticsearch/reference/current/common-options.html#date-math[Date Math format], see also Additional look-back time)

Maximum alerts per execution: 100

References:

• https://threathunterplaybook.com/notebooks/windows/06_credential_access/WIN-180815210510.html
• https://threathunterplaybook.com/library/windows/active_directory_replication.html?highlight=dcsync#directory-replication-services-auditing
• https://github.com/SigmaHQ/sigma/blob/master/rules/windows/builtin/security/win_ad_replication_non_machine_account.yml
• https://github.com/atc-project/atomic-threat-coverage/blob/master/Atomic_Threat_Coverage/Logging_Policies/LP_0027_windows_audit_directory_service_access.md
• https://attack.stealthbits.com/privilege-escalation-using-mimikatz-dcsync
• https://www.thehacker.recipes/ad/movement/credentials/dumping/dcsync

Tags:

• Elastic
• Host
• Windows
• Threat Detection
• Credential Access
• Active Directory

Version: 1

Rule authors:

• Elastic

Rule license: Elastic License v2

event.action : "Directory Service Access" and event.code : "4662" and
 winlog.event_data.Properties : (*DS-Replication-Get-Changes* or *DS-Replication-Get-Changes-All* or *DS-Replication-Get-Changes-In-Filtered-Set* or *1131f6ad-9c07-11d1-f79f-00c04fc2dcd2* or *1131f6aa-9c07-11d1-f79f-00c04fc2dcd2* or *89e95b76-444d-4c62-991a-0facbeda640c*) and
 not winlog.event_data.SubjectUserName : (*$ or MSOL_*)

Framework: MITRE ATT&CKTM

• Tactic:

  • Name: Credential Access
  • ID: TA0006
  • Reference URL: https://attack.mitre.org/tactics/TA0006/

• Technique:

  • Name: OS Credential Dumping
  • ID: T1003
  • Reference URL: https://attack.mitre.org/techniques/T1003/

• Sub-technique:

  • Name: DCSync
  • ID: T1003.006
  • Reference URL: https://attack.mitre.org/techniques/T1003/006/