Trojan:Win32/Chopper.A

Guidance for individual users

Keep your operating system and antivirus products up to date.

To learn more about preventing trojans or other malware from affecting individual devices, read about preventing malware infection.

Guidance for enterprise administrators

Apply these mitigations to reduce the impact of this threat. Check the recommendations card for the deployment status of monitored mitigations.

• Keep public-facing servers up to date to defend against malicious activity. As prime targets for threat actors, public-facing servers need additional monitoring and security. User input validation, file integrity monitoring, behavioral monitoring, and web application firewalls can all help to better secure these servers.
• Read our ransomware as a service blog for advice on developing a holistic security posture to prevent ransomware, including credential hygiene and hardening recommendations.
• Turn on cloud-delivered protection and automatic sample submission on Microsoft Defender Antivirus. These capabilities use artificial intelligence and machine learning to quickly identify and stop new and unknown threats.
• Ensure internet-facing assets have the latest security updates. Audit these assets regularly for suspicious activity.
• Practice the principle of least privilege and maintain credential hygiene. Avoid the use of domain-wide, admin-level service accounts. Restricting local administrative privileges can help limit the installation of RATs and other unwanted applications.