Facebook revealed that it was the target of a "sophisticated attack" by hackers last month.
The online social network said the attack occurred when an employee visited a website for mobile app development that had been compromised by hackers and was distributing malware.
Facebook said in a blog post that it was not the only company to have been attacked in this way.
“Last month, Facebook security engineers discovered that our systems had been the target of a highly sophisticated attack,” the company said.
The malware had been transferred to our employee's laptop, the company continues. "As soon as we discovered the presence of the malware, we restored all infected machines, notified authorities and began an investigation that continues to this day."
"We have no evidence yet that any of our users' data was affected by this attack," Facebook said in a blog post.
