Facebook has revealed it was targeted by hackers last month, but says user data was not compromised.

The social media network says its security systems were targeted in a ‘sophisticated’ attack when a handful of employees visited a mobile developer website.

Facebook Hit in 'Sophisticated' Attack

 

The compromised website hosted an exploit which then allowed malware to be installed onto the employee laptops.

A spokesman from Facebook said: “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.”

User Data Compromised?

The US-company said it has no evidence that suggests Facebook user data was compromised in the attack.

It said it invests heavily in preventing, detecting and responding to threats that target its infrastructure as it is frequently targeted by hackers wanting to disrupt or access its data.

Facebook is now working closely with internal engineering teams, security teams at other companies, and with law enforcement authorities, in a bid to learn everything about the attack, and to look at how it can prevent similar incidents in the future.

System Vulnerability

After analyzing the compromised website where the attack originated, Facebook found the site was using a previously unseen ‘zero-day’ exploit to bypass the built-in protections from Java sandbox, allowing it to install the malware onto the laptops.

Facebook said it flagged a suspicious domain in its corporate DNS logs and soon tracked it back to an employee laptop.

Upon conducting a ‘forensic examination’ of that laptop, it identified a malicious file, so subsequently carried out a company-wide system search and as a result, flagged several other compromised employee laptops.

Are Hackers Taking Over?

Facebook said it was not alone in the attack and investigations into the breach are continuing,

“We immediately took steps to start sharing details about the infiltration with the other companies and entities that were affected,” a Facebook spokesman added.

“We plan to continue collaborating on this incident through an informal working group and other means.”

As reported by TechBeat earlier this month, social media giant Twitter was a victim of an internet security attack.

It was thought information from 250,000 users of the micro-blogging site may have been compromised by hackers. The New York Times and Wall Street Journal also reported breaches of their systems.

[Image via arstechnica]