Mimikatz is a powerful and widely recognized cybersecurity tool primarily used for memory scraping and credential dumping from Windows operating systems. While it was initially developed by researcher Benjamin Delpy to demonstrate security weaknesses in Windows, it has since been heavily co-opted by threat actors to facilitate advanced attacks.
Primary Functions of Mimikatz
The tool’s core functionality revolves around its ability to extract sensitive authentication data directly from a system’s memory. Key technical capabilities include:
- Credential Extraction: Mimikatz can retrieve plaintext passwords, password hashes (NTLM/LM), PIN codes, and Kerberos tickets from memory.
- Targeting System Components: It possesses specific modules to acquire information from the Local Security Authority (LSA), the Security Account Manager (SAM) table, the credential vault, and the Data Protection API (DPAPI), which can even reveal credentials cached by web browsers.
- Advanced Authentication Attacks:
- Pass-the-Hash (PtH): It allows attackers to authenticate and execute arbitrary commands using only a password hash, bypassing the need for a plaintext password.
- Pass-the-Ticket (PtT) and Golden Tickets: It can extract Kerberos tickets to create “Golden Tickets,” enabling an attacker to impersonate any user account with indefinite validity.
- DCShadow: This module can temporarily set a compromised computer to act as a Domain Controller to make unauthorized updates to Active Directory.
- SID-History Injection: It can append Security Identifiers (SIDs) to a user’s SID-History to expand access across multiple domains.
Strategic Purpose in the Attack Lifecycle
Within the context of the Cyber Kill Chain or the MITRE ATT&CK framework, Mimikatz is utilized for several critical objectives:
- Privilege Escalation: By dumping credentials from a system, attackers seek to gain administrative or “root-level” permissions that they did not initially possess.
- Lateral Movement: Attackers use the stolen credentials or Kerberos tickets to move from an initially compromised host to other, more valuable systems across the network.
- Persistence: Techniques like Golden Tickets and modifying Active Directory through DCShadow allow threat actors to maintain a long-term presence in the environment even if their initial entry point is closed or a password is reset.
Analogy: Mimikatz is like a master locksmith who discovers that a building manager keeps all the physical master keys and security codes in an unlocked drawer (the system memory) instead of a secure safe. Rather than trying to pick the lock on every individual office door, the locksmith simply reaches into that drawer to take the master key, granting them unrestricted access to every room in the building and the ability to change the locks for anyone else.