OS Credential Dumping: Cached Domain Credentials
Adversaries may attempt to access cached domain credentials used to allow authentication to occur in the event a domain controller is unavailable.
On Windows Vista and newer, the hash format is DCC2 (Domain Cached Credentials version 2) hash, also known as MS-Cache v2 hash. 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 to recover the plaintext password.
Note: Cached credentials for Windows Vista are derived using PBKDF2.
|Active Directory Configuration||
Consider adding users to the "Protected Users" Active Directory security group. This can help limit the caching of users' plaintext credentials.
|Operating System Configuration||
Consider limiting the number of cached credentials (HKLM\SOFTWARE\Microsoft\Windows NT\Current Version\Winlogon\cachedlogonscountvalue)
Ensure that local administrator accounts have complex, unique passwords across all systems on the network.
|Privileged Account Management||
Do not put user or admin domain accounts in the local administrator groups across systems unless they are tightly controlled, as this is often equivalent to having a local administrator account with the same password on all systems. Follow best practices for design and administration of an enterprise network to limit privileged account use across administrative tiers.
Limit credential overlap across accounts and systems by training users and administrators not to use the same password for multiple accounts.
Monitor processes and command-line arguments for program execution that may be indicative of credential dumping. Remote access tools may contain built-in features or incorporate existing tools like Mimikatz. PowerShell scripts also exist that contain credential dumping functionality, such as PowerSploit's Invoke-Mimikatz module, which may require additional logging features to be configured in the operating system to collect necessary information for analysis.
Detection of compromised Valid Accounts in-use by adversaries may help as well.
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