High Number of Process and/or Service Terminations Detected

This detection identifies a suspicious pattern of rapid process and service terminations on a Windows host. Attackers commonly stop services and kill processes to disable security tools, release file locks for encryption, or disrupt normal system operations. The rule specifically looks for multiple instances of termination-related commands executed via net.exe, sc.exe, or taskkill.exe within a short timeframe. This activity can be indicative of an attacker preparing a system for ransomware deployment or attempting to evade defenses. The detection focuses on Windows systems, leveraging process monitoring logs. This behavior aligns with tactics used to impair defenses and achieve significant impact on compromised systems.

Attack Chain

1. The attacker gains initial access to the Windows host (e.g., through phishing or exploitation).
2. The attacker escalates privileges to obtain necessary permissions to terminate processes and services.
3. The attacker uses net.exe to stop specific services, such as backup solutions or security software.
4. The attacker employs sc.exe to delete services, preventing them from restarting automatically.
5. The attacker utilizes taskkill.exe with flags like /F, /IM, or /PID to forcefully terminate processes.
6. The attacker repeats these steps, rapidly terminating multiple processes and services.
7. The attacker prepares the system for ransomware deployment by disabling security measures.
8. The attacker deploys ransomware, encrypting data and demanding a ransom for its recovery.

Impact

Successful exploitation leads to disruption of critical services, disabling of security controls, and potential data loss. If an attacker successfully terminates security solutions, they can significantly increase the likelihood of successful ransomware deployment or data exfiltration. The impact can range from temporary service outages to complete system compromise and data encryption, resulting in financial losses, reputational damage, and operational disruption.

Recommendation

• Deploy the High Number of Process Terminations via Taskkill and High Number of Service Terminations via SC Sigma rules to your SIEM and tune for your environment.
• Investigate any alerts triggered by the rules, focusing on the processes terminated and the user accounts involved.
• Enable process creation logging with command-line arguments to ensure the rules have sufficient data to function effectively.
• Review the references provided to understand attacker techniques and improve detection strategies.
• Implement network segmentation to limit the lateral movement of attackers.
• Regularly review and update security policies to prevent unauthorized process termination.