File photo: AP

San Francisco - A sophisticated hacking attack managed to penetrate Facebook's computer system but there was no evidence that user data was compromised, the social networking giant said.

The attack occurred when employees visited a mobile developer website that was compromised and which allowed malware to be installed on their computers.

Facebook said the malware exploited a flaw in Oracle's Java program, but was later patched.

News of the attack will raise red flags among privacy advocates, coming just weeks after Twitter urged more than 250,000 users to change their passwords after their information was compromised. - Sapa-dpa