Hackers suspected to work for the Chinese government have used a new malware called PortDoor to infiltrate systems of an engineering company that designs submarines for the Russian Navy. The threat actor targeted Rubin Central Design Bureau for Marine Engineering in Saint Petersburg, a defense contractor that designed most of Russia s nuclear submarines. The method for delivering the backdoor was a weaponized RTF document attached to an email addressed to the company CEO, Igor V. Vilnit. The attacker lured the recipient to open the malicious document with a general description for an autonomous underwater vehicle.
Source: https://www.bleepingcomputer.com/news/security/suspected-chinese-state-hackers-target-russian-submarine-designer/