A threat actor named Mr_Rot13 has been attributed to the exploitation of a recently disclosed critical cPanel flaw to deploy a backdoor codenamed Filemanager on compromised environments. The attack exploits CVE-2026-41940, a vulnerability impacting cPanel and WebHost Manager (WHM) that could result in an authentication bypass and allow remote attackers to gain elevated control of the control panel. According to a new report from QiAnXin XLab, the security defect has been exploited by a number of threat actors shortly after its public disclosure late last month, resulting in malicious behaviors like cryptocurrency mining, ransomware, botnet propagation, and backdoor implantation. "Monitoring data shows that more than 2,000 attacker source IPs worldwide are currently involved in automated…