The malicious FriarFox browser extension
https://www.bleepingcomputer.com/news/security/malicious-firefox-extension-allowed-hackers-to-hijack-gmail-accounts/
Several Tibetan organizations were targeted in a cyber-espionage campaign by a state-backed hacking group using a malicious Firefox extension designed to hijack Gmail accounts and infect victims with malware.
The attacks coordinated by the TA413 Chinese-linked APT group started in January and continued throughout February, according to a Proofpoint report published on Thursday.