{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata — refreshed continuously.","feed_url":"https://feed.craftedsignal.io/tags/dcsync/","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cves":[],"_cs_exploited":false,"_cs_products":["Active Directory"],"_cs_severities":["medium"],"_cs_tags":["credential-access","persistence","active-directory","dcsync"],"_cs_type":"advisory","_cs_vendors":["Microsoft"],"content_html":"\u003cp\u003eThis detection rule identifies modifications to the \u003ccode\u003enTSecurityDescriptor\u003c/code\u003e attribute within Active Directory (AD) objects that grant DCSync-related permissions to a user or computer account. This technique allows attackers to create a persistent backdoor, enabling them to re-obtain access to user and computer account hashes. The modification involves assigning specific GUIDs that represent replication rights (\u003ccode\u003e1131f6ad-9c07-11d1-f79f-00c04fc2dcd2\u003c/code\u003e, \u003ccode\u003e1131f6aa-9c07-11d1-f79f-00c04fc2dcd2\u003c/code\u003e, \u003ccode\u003e89e95b76-444d-4c62-991a-0facbeda640c\u003c/code\u003e) to an account\u0026rsquo;s security descriptor. This allows the attacker to then use DCSync to retrieve credentials from the domain, effectively bypassing normal authentication mechanisms.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker gains initial access to an account with sufficient privileges to modify Active Directory objects (e.g., Domain Admin).\u003c/li\u003e\n\u003cli\u003eThe attacker uses AD management tools (PowerShell, ADSI Edit, etc.) to target a specific user or computer account.\u003c/li\u003e\n\u003cli\u003eThe attacker modifies the \u003ccode\u003enTSecurityDescriptor\u003c/code\u003e attribute of the targeted account.\u003c/li\u003e\n\u003cli\u003eThe attacker grants replication rights to the targeted account by adding specific Access Control Entries (ACEs) containing the GUIDs \u003ccode\u003e1131f6ad-9c07-11d1-f79f-00c04fc2dcd2\u003c/code\u003e, \u003ccode\u003e1131f6aa-9c07-11d1-f79f-00c04fc2dcd2\u003c/code\u003e, and \u003ccode\u003e89e95b76-444d-4c62-991a-0facbeda640c\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003eThe attacker uses the DCSync technique, impersonating a domain controller, to request password hashes.\u003c/li\u003e\n\u003cli\u003eThe Active Directory server, believing the request is legitimate due to the granted replication rights, provides the attacker with the requested credential information.\u003c/li\u003e\n\u003cli\u003eThe attacker obtains password hashes for domain users and computers.\u003c/li\u003e\n\u003cli\u003eThe attacker uses the obtained credentials for lateral movement, privilege escalation, or data exfiltration.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation allows attackers to compromise the entire Active Directory domain by gaining access to sensitive credential data. This could lead to complete control over the network, including access to critical systems, sensitive data, and the ability to disrupt business operations. The modification of security descriptors creates a persistent backdoor that can be used repeatedly to harvest credentials.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eEnable Audit Directory Service Changes to generate the necessary event logs for detection (\u003ca href=\"https://ela.st/audit-directory-service-changes)\"\u003ehttps://ela.st/audit-directory-service-changes)\u003c/a\u003e.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rule provided below to detect unauthorized modifications to the \u003ccode\u003enTSecurityDescriptor\u003c/code\u003e attribute. Tune the rule to exclude legitimate administrative accounts or scripts that may perform authorized modifications.\u003c/li\u003e\n\u003cli\u003eMonitor Windows Security Event Logs (event code 5136) for changes to the \u003ccode\u003enTSecurityDescriptor\u003c/code\u003e attribute and investigate any unexpected modifications, focusing on the presence of DCSync-related GUIDs.\u003c/li\u003e\n\u003cli\u003eRegularly review and audit Active Directory permissions, focusing on accounts with replication rights, to ensure they are legitimate and necessary.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-05-04T14:17:05Z","date_published":"2026-05-04T14:17:05Z","id":"/briefs/2026-05-dcsync-backdoor/","summary":"Attackers can modify Active Directory object security descriptors to grant DCSync rights to unauthorized accounts, creating a backdoor to extract credential data.","title":"Potential Active Directory Replication Account Backdoor","url":"https://feed.craftedsignal.io/briefs/2026-05-dcsync-backdoor/"}],"language":"en","title":"CraftedSignal Threat Feed — Dcsync","version":"https://jsonfeed.org/version/1.1"}