Chinese hackers targeted and breached government and government-linked organizations worldwide in recent attacks targeting a Barracuda Email Security Gateway (ESG) zero-day.
The attacks, which were motivated by espionage, were carried out by a threat actor tracked as UNC4841. The attackers exploited a zero-day vulnerability in the ESG appliance to gain remote access to compromised systems. They then deployed malware, including SeaSpy and Saltwater, to steal data from the systems.
UNC4841, the threat actor, performed targeted exfiltration from systems utilized by high-profile government and high-tech users. On May 20, the vulnerability was first exploited, leading Barracuda to issue a fix and notify customers.
The business eventually revealed that the zero-day vulnerability had been exploited for at least seven months, resulting in data theft and the deployment of previously unknown malware.
The attacks were particularly focused on entities in the Americas, with almost a third of the appliances hacked belonging to government agencies. In the United States, nearly 17% of the affected organizations were local governments.
Barracuda warned customers about the vulnerability on May 20, but the attacks had been ongoing for at least seven months prior to that. The FBI has warned that even patched appliances are still at risk of being compromised.
The sources for this piece include an article in BleepingComputer.