Ransomware a.k.a ClearEnergy affects a massive range of PLC models of worlds largest manufacturers of SCADA and Industrial Control Systems. Schneider Electric, Allen-Bradley, General Electric (GE) and more vendors are vulnerable to ClearEnergy ransomware. ClearEnergy attack is based on the most comprehensive and dangerous vulnerability that ever found in Critical Infrastructure, SCADA, ICS Systems and affects a wide range of vulnerable products from different manufacturers and vendors. It relies on the security flaws in the UMAS protocol in the common protocol in critical infrastructure and industrial control systems.”]
Source: http://securityaffairs.co/wordpress/57731/malware/clearenergy-ransomware-scada.html