Detecting Kerbrute

Rule type:

Correlation

Rule description:

Kerbrute is a command-line tool that is designed to leverage the Kerberos protocol to execute attacks against Active Directory (AD) domains. Attackers use this tool to enumerate valid AD usernames, performing attacks such as password spraying and brute-force.

Impact:

It can be used by adversaries in the following ways:

• Interception of NTLM authentication requests
• Credential compromise
• Password spraying
• Data breaches

Data source:

Windows:

Required configuration: The rules is based on the process creation and termination. Prerequisites required are installing and configuring Sysmon, enabling audit process creation audit policy, and the command line auditing.

Relevant MITRE ATT&CK techniques and tactics:

Software

Criteria:

Command line contains kerbrute

'Kerbrute'- Use of 'kerbrute' in command line may suggest that attackers are attempting to launch a brute-force and password spraying attack to perform data exfiltration,unauthorized access, and more malicious activities.

When to enable this rule:

Enabling this rule will help you meet the security standards' requirements listed below:

Security standards (NIST CSF 2.0):

DE.CM-09: Computing hardware and software, runtime environments, and their data are monitored to find potentially adverse events

When this rule is triggered, you're notified when Kerbrute is being used within the network. This enables you to stop the runtime activity and prevent attacker goals.

PR.PS-05: Installation and execution of unauthorized software are prevented

When this rule is triggered, you're notified when Kerbrute is being used within the network. This enables you to detect the use of unauthorized softwares within the network and prevent credential theft and other attacker goals.

Known false positives: The blue teams might use the tool to test the effectiveness of their defensive measures and incident response protocols.

Next steps:

When this alert is triggered, the following measures can be implemented:

• Identification: Identify the alert as a new incident or within an ongoing incident.
• Analysis: Analyze the impact and extent of the compromise to comprehend the severity of the attack.
• Response: Respond promptly by initiating an automated workflow to cease the malicious process.
• Strong Password Policy Enforcement: Ensure a strong password policy is adhered to across the organization.