Gawker.com and other websites owned by Gawker Media were attacked by hackers over the weekend, prompting the sites to stop publishing new material and advise users to change their passwords.

A group calling themselves Gnosis has hit Gawker Media, the blog empire built by Nick Denton, and had gained access to the company's servers and accessed information about more than one million registered users of sites like Gizmodo and Jezebel as well as Gawker.com.

Hackers said Gawker writers had been critical of the online message board 4chan, a group that mounts attacks on Web sites and individuals.

[Fu**] you Gawker, how's this for 'script kids'? Your empire has been compromised. Your servers, your database's, online accounts, and source code have all ripped to shreds! You wanted attention; well guess what, you've got it now!, according to a comment by Gnosis in the Torrent file.

You would think a site that likes to mock people, such as gawker, would have better security and actually have a clue what they are doing. But as we've proven, those who think they are beyond our reach aren't as safe as they would like to think! the hackers added.

Gawker acknowledged the hacker attack and said this weekend Gawker Media's servers were compromised, resulting in a security breach at Lifehacker, Gizmodo, Gawker, Jezebel, io9, Jalopnik, Kotaku, Deadspin, and Fleshbot.

Our user databases appear to have been compromised. The passwords were encrypted. But simple ones may be vulnerable to a brute-force attack. You should change your Gawker password and on any other sites on which you've used the same passwords, Gawker.com said in a statement on its website.

We're deeply embarrassed by this breach. We should not be in the position of relying on the goodwill of the hackers who identified the weakness in our systems. And, yes, the irony is not lost on us, the statement added.

The latest attack is a black mark in the history of eight-year old Gawker, which has long been a pioneer in blogging and online publishing. Of late it has been working on redesigning its Web sites.

The attack on Gawker.com is not related to the recent cyber attacks tied to WikiLeaks. Last week, hackers targeted Web sites like PayPal, MasterCard, Visa, and other companies that severed ties with WikiLeaks, the organization that released confidential and sensitive government information, leading to the arrest of its founder Julian Assange.