Facebook spam attack results in graphic images for some users

Facebook said a deliberate spam attack was behind a flood of graphic images that some users had reported seeing in their news feeds.

The issue, which first surfaced last week, had largely been resolved by late Tuesday, said Frederic Wolens, a spokesman at the company. Mr. Wolens said the attack lured users into copying and pasting a Web address into their browser with the promise of showing them a neat video or telling them who was viewing the profile. Instead, that Web site installed malicious software that began filling their news feeds with violent and pornographic images without their knowledge.

Mr. Wolens declined to say how many users had been affected, but did say it was "a small minority." Facebook said no user data or accounts were compromised during the attack.

"Our team responded quickly and we have eliminated most of the spam caused by this attack," the company said. "We are now working to improve our systems to better defend against similar attacks in the future."

Some around the Web have speculated that Anonymous, the hacker movement, might be responsible for the attack. But Facebook said the attack had been designed for financial gain. The junk posts sent users to affiliate sites that could generate revenue for the spammers.