China's National Computer Virus Emergency Response Center and the National Engineering Laboratory for Computer Virus Prevention Technology have released an official warning after multiple real-world incidents of the Sorry ransomware struck Linux Web servers across the country.
Attack Vector and Initial Access
The ransomware exploits an authorization vulnerability in WebPros cPanel tracked as CVE-2026-41940 (CNNVD-202604-5641). Attackers use the flaw to obtain administrative privileges on internet-facing servers without relying on weak SSH passwords or outdated exploits. Once inside, the malware deploys a process that masquerades as a legitimate sshd daemon, making detection difficult through casual inspection of running processes.
Full Attack Chain
Security researchers outlined the six-stage operation:
- Network intrusion via the cPanel flaw followed by deployment of the disguised ransomware.
- Environment reconnaissance that generates a unique victim identifier containing username, hostname, CPU count, OS details, and active network interfaces, then exfiltrates the profile.
- Obstacle removal by terminating database, security, and backup services before encryption begins.
- Data theft of business data, configuration files, and internal documents for double-extortion purposes.
- File encryption using AES with RSA-wrapped keys; encrypted files receive the .sorry extension. Officials confirm no reliable recovery method exists without the attackers' key.
- Lateral movement by scanning SSH ports 22, 2222, and 22222 and propagating via weak passwords to other Linux hosts.
Why the Threat Matters
The advisory explicitly notes that the ransomware runs on most mainstream Linux distributions, including domestic Xinchuang operating systems. Its built-in lateral movement capability raises the risk of widespread internal network compromise from a single exposed server. The pre-encryption termination of backup services further reduces recovery options for organizations that keep backups on the same host.
Immediate Mitigation Steps
Administrators should perform the following checks without delay:
- Verify cPanel/WHM or WP Squared versions and apply the latest patches addressing CVE-2026-41940.
- Inspect running processes for anomalous sshd instances and confirm executable paths with commands such as ls -l /proc/<PID>/exe.
- Remove public internet exposure of management panels, remote access ports, and database interfaces; enforce VPNs, bastion hosts, source IP allowlists, and multi-factor authentication.
- Replace weak passwords on SSH ports 22, 2222, and 22222 and eliminate password reuse across hosts.
- Ensure backup services and data are isolated from production systems and stored offline.
- Avoid downloading any purported decryptors or communication tools promoted online, as they are likely secondary malware.
- Submit suspicious files to the National Computer Virus Collaborative Analysis Platform (virus.cverc.org.cn) for analysis.
Security teams are advised to complete these actions before the end of the business day to prevent servers from being encrypted with the .sorry extension.
