US videogame studio Bethesda Softworks said its websites were hit with a cyberattack over the weekend and warned that hackers may have stolen some user data.
"A hacker group attempted an unlawful intrusion of our websites to gain access to data," the studio behind hot videogames including Fallout and Rage said in a blog post.
"We believe we have taken appropriate action to protect our data against these attacks," the message continued.
Bethesda said no personal financial information or credit card data was swiped but that hackers may have gained access to some user names, email addresses, or passwords.
The videogame maker advised fans to change passwords at its websites, including online pages for community forums and a statistics site for Brink videogame players.
"We regret any inconvenience that these attacks on us cause for you," Bethesda said. "These attacks will be evaluated to determine if there are any additional protections we might take that would be prudent."
The group of hackers called Lulz Security took credit for the Bethesda hack yesterday, saying they broke in weeks ago and looted data.
Lulz Security made publicly available what the group said it took from Bethesda, minus stolen information about more than 200,000 Brink users.
"We actually like this company and would like for them to speed up the production of Skyrim, so we'll give them one less thing to worry about," the Lulz message read.
Skyrim is an eagerly-anticipated new videogame due for release by Bethesda in November.
Hackers have staged unrelenting attacks in recent months, with targets ranging from Gmail accounts and Sony's online entertainment networks to military weapons maker Lockheed Martin and police in Spain.
Lulz Security has claimed responsibility for several of the cyberattacks,