Facebook announced this afternoon that they received a series of sophisticated attacks by a hacker group that cannot be identified. Facebook had posted in its blog that the attack happened last month when a few of its employees visited a specific mobile developer’s website. As a result of going to the mobile developer’s website, malware software was installed on the Facebook employees’ laptops.
The hacker group ended up using what’s called “zero-day” Java Exploit, which can be found in Oracle software. You might want to start paying attention to which sites you’re visiting because if you have Oracle Java installed and enabled, your computer can be at risk of getting compromised too.
Facebook stated that as soon as they found out about malware being installed on its employees computers, they informed law enforcement, remediated infected machines, and started the investigation, which is still in progress. The Facebook blog also notes that they "found no evidence that Facebook user data was compromised."