https://www.bleepingcomputer.com/news/security/barracuda-fixes-new-esg-zero-day-exploited-by-chinese-hackers/

Network and email security firm Barracuda says it remotely patched all active Email Security Gateway (ESG) appliances on December 21 against a zero-day bug exploited by UNC4841 Chinese hackers.

The company deployed a second wave of security updates a day later on already compromised ESG appliances where the attackers deployed SeaSpy and Saltwater malware.