A threat actor believed to be working on behalf of Chinese state-sponsored interests was recently observed targeting a Russia-based defense contractor involved in designing nuclear submarines for the naval arm of the Russian Armed Forces.

Rubin Design Bureau is a submarine design center located in Saint Petersburg, accounting for the design of over 85% of submarines in the Soviet and Russian Navy since its origins in 1901, including several generations of strategic missile cruiser submarines.

https://www.cybereason.com/blog/portdoor-new-chinese-apt-backdoor-attack-targets-russian-defense-sector