Detecting the presence of VulnRecon tool

Prerequisite:

The rule requires sysmon/auditing to be enabled for proper functioning.

Rule type:

Correlation rule

Rule description:

This correlation rule aims to identify the use of VulnRecon, a custom-developed tool designed for local privilege escalation within Windows environments.

Data source:

Windows: Network traffic

Relevant MITRE ATT&CK techniques and tactics:

Tactics: TA0005 - Defense Evasion, TA0004 - Privilege Escalation, TA0007 - Discovery

Techniques: T1036 - Masquerading, T1548 - Abuse Elevation Control Mechanism, T1082 - System Information Discovery

Criteria:

Original file name contains VulnRecon: This condition checks if the filename of a logged event literally contains the text "VulnRecon". For instance, if a file named "VulnRecon_Report.txt" is accessed or modified, this condition would be met.

Process name contains VulnRecon: This condition examines the name of the process associated with a logged event. If a process like "VulnRecon.exe" is involved in the event, this condition would be triggered.

Command line contains VulnRecon: This condition inspects the command line arguments used by a process during a logged event. If the command line includes the text "VulnRecon", this condition would be satisfied.

When to enable this rule:

Enable this rule when the user wants to detect suspicious activities that might indicate local privilege escalation attempts, particularly those involving the use of custom tools.

Compliance mapping (NIST, CIS):

Enabling this rule will help you comply with the below security standards' requirements:

NIST Cybersecurity Framework (CSF):

• Irregular Access to Credential Stores (DE.CM-1): Detection of attempts to access or manipulate privileged accounts and resources.
• Unusual Network Traffic Patterns (DE.AE-1): Monitoring for unusual network traffic indicative of BloodHound's reconnaissance activities.
• Security Log Anomalies (DE.CM-7): Alerting on suspicious activities associated with privilege escalation or unusual access patterns.

CIS:

• Control 8: Malware Defense: Implement mechanisms to detect and prevent the execution of BloodHound and similar tools used for Active Directory reconnaissance.
• Control 6: Maintenance, Monitoring, and Analysis of Audit Logs: Analyze audit logs for anomalies indicating BloodHound's presence or unauthorized access attempts.

Next steps:

Upon triggering this alert, the following actions can be taken:

• Identification: Mark this alert as a part of an existing incident or initiate a new incident. Assigning the incident to an analyst for in-depth examination.
• Analysis: Conduct an impact investigation and thoroughly analyze the degree of compromise utilizing the Incident Workbench to gain insights into the threat's severity.
• Response: Initiate automated workflow execution to swiftly terminate the identified malicious process, leveraging Workflows for prompt mitigation.