Query: EDR alert: possible DCSync (T1003.006)
Matching passage: T1003.006 DCSync. Tactics: credential access. Description: Adversaries may attempt to access credentials and other sensitive information by abusing a Windows Domain Controller's application programming interface (API)(Citation: Microsoft DRSR Dec 2017) (Citation: Microsoft GetNCCChanges) (Citation: Samba DRSUAPI) (Citation: Wine API samlib.dll) to simulate the replication process from a remote domain controller using a technique called DCSync. Members of the Administrators, Domain Admins, and Enterprise Admin groups or computer accounts on the domain controller are able to run DCSync to pull password data(Citation: ADSecurity Mimikatz DCSync) from Active Directory, which may include current and historical hashes of potentially useful accounts such as KRBTGT and Administrators. The hashes can then in turn be used to create a [Golden Ticket](https://attack.mitre.org/techniques/T1558/001) for use in [Pass the Ticket](https://attack.mitre.org/techniques/T1550/003)(Citation: Harmj0y Mimikatz and DCSync) or change an account's password as noted in [Account Manipulation](https://attack.mitre.org/techniques/T1098).(Citation: InsiderThreat ChangeNTLM July 2017) DCSync functionality has been included in the "lsadump" module in [Mimikatz](https://attack.mitre.org/software/S0002).(Citation: GitHub Mimikatz lsadump Module) Lsadump also includes NetSync, which performs DCSync over a legacy replication protocol.(Citation: Microsoft NRPC Dec 2017)
Near-miss passage: T1003.005 Cached Domain Credentials. Tactics: credential access. Description: Adversaries may attempt to access cached domain credentials used to allow authentication to occur in the event a domain controller is unavailable.(Citation: Microsoft - Cached Creds) On Windows Vista and newer, the hash format is DCC2 (Domain Cached Credentials version 2) hash, also known as MS-Cache v2 hash.(Citation: PassLib mscache) The number of default cached credentials varies and can be altered per system. This hash does not allow pass-the-hash style attacks, and instead requires [Password Cracking](https://attack.mitre.org/techniques/T1110/002) to recover the plaintext password.(Citation: ired mscache) On Linux systems, Active Directory credentials can be accessed through caches maintained by software like System Security Services Daemon (SSSD) or Quest Authentication Services (formerly VAS). Cached credential hashes are typically located at `/var/lib/sss/db/cache.[domain].ldb` for SSSD or `/var/opt/quest/vas/authcache/vas_auth.vdb` for Quest. Adversaries can use utilities, such as `tdbdump`, on these database files to dump the cached hashes and use [Password Cracking](https://attack.mitre.org/techniques/T1110/002) to obtain the plaintext password.(Citation: Brining MimiKatz to Unix) With SYSTEM or sudo access, the tools/utilities such as [Mimikatz](https://attack.mitre.org/software/S0002), [Reg](https://attack.mitre.org/software/S0075), and secretsdump.py for Windows or Linikatz for Linux can be used to extract the cached credentials.(Citation: Brining MimiKatz to Unix) Note: Cached credentials for Windows Vista are derived using PBKDF2.(Citation: PassLib mscache)