Facebook has been hacked in a “sophisticated attack” by hackers who had knowledge of a previously unknown loophole in the system.
Facebook explained in a blog post: “Last month, Facebook Security discovered that our systems had been targeted in a sophisticated attack. This attack occurred when a handful of employees visited a mobile developer website that was compromised.
“The compromised website hosted an exploit which then allowed malware to be installed on these employee laptops. The laptops were fully-patched and running up-to-date anti-virus software.
“As soon as we discovered the presence of the malware, we remediated all infected machines, informed law enforcement, and began a significant investigation that continues to this day.”
The malware that attacked its systems used a previously unknown loophole, taking advantage of a flaw in Java software made by Oracle, a mobile developer.
Facebook has insisted that no personal information of users had been compromised by the attack and that it was not the only company to have been attacked in this way.
This news comes after Twitter reported that 250,000 user details, including usernames, passwords and email addresses, were stolen by hackers. It said it was "not the work of amateurs".
The New York Times, Washington Post and Wall Street Journal have all recently been subjected to hacking attacks, accusing China of targeting their computer systems.