Shares of Facebook (NASDAQ:FB) declined in late afternoon hours after saying it was the target of a series of attacks from unidentified hackers. The social media company explains in a statement, “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.” There is no evidence so far that any user data was compromised.