Use Facebook to log into other apps? Hackers may have breached them too

Facebook said on Tuesday that investigators have determined that hackers did not access other sites that use the social networking site’s single sign-on in a massive cyber attack that the company disclosed last week.

“We analysed third-party access during the time of the attack we have identified. That investigation has found no evidence that the attackers accessed any apps using Facebook Login,” said Guy Rosen, a Facebook vice-president overseeing security, in a statement sent to Reuters.

The announcement comes after Facebook last week disclosed its worst-ever security breach, saying hackers had stolen login codes that allowed them to access nearly 50 million Facebook accounts. Facebook shares fell for a third day on Tuesday, dropping 1.9 per cent to $159.33. Rosen had warned on a Friday conference call that the hackers could have also accessed third-party websites and apps that allow uses to access their accounts using Facebook logins.

Some security experts, including a former Facebook executive, said the company may have painted a dire, worst-case scenario when it disclosed the attack on Friday to ensure that compliance with strict new European Union privacy rules that took effect in late May.

The EU’s General Data Protection Regulation, or GDPR, imposes steep penalties if companies fail to follow rules that include a requirement that they disclose breaches within 72 hours of discovery. That is a tight window that security experts say does not give investigators adequate time to determine the impact of the breach. “Interesting impact of the GDPR 72-hour deadline: Companies announcing breaches before investigations are complete,” former senior Facebook Chief Information Security Officer Alex Stamos said in a tweet.

The result is that “everybody is confused on actual impact, lots of rumours,” he tweeted, adding that “month later, truth is included in official filing.”