As it became known, Sunday, hackers attacked Google's ultra-popular video sharing site YouTube, exploiting a cross-site scripting (XSS) vulnerability. Thus, the section suffered mostly appeared to be the section where users post comments.

This malicious attack compromised YouTube cookies of users who visited a compromised page, but it couldn't be used to access their Google accounts.

In order to prevent further attacks users should log out of their account and log back in again, as Google spokesman advised.

The attackers targeted singer Justin Bieber, incorporating code into YouTube pages devoted to him so that visitors saw tasteless messages pop up about the teen star, and were also redirected to external sites with adult content.

Actually, the attack itself didn't involve malware infections, such a risk is inherent whenever users visit any Web page, such as the ones attackers redirected users to. And it’s still not clear if those landing pages contained malware, but most up-to-date anti-virus software is designed to protect against those threats, according to some sources familiar with the deal.