The Web site for the recording industry's anti-piracy lobby has been inaccessible for several days, possibly the victim of a computer virus specifically targeting the site.
The Recording Industry Association of America's site at riaa.com was among the targets named in the "MyDoom.F" virus, which Internet security firms spotted last month. The site has been down since Wednesday and remained offline Monday.
"We are working on getting it back online," RIAA spokesman Jonathan Lamy said, declining to elaborate.
The virus was programmed to activate between the 17th and 22nd of any month, said Vincent Gullotto, vice president of McAfee's antivirus emergency response team.
It's not clear whether the virus actually caused an Internet traffic jam that shut down the site, or if the RIAA opted to take the site down in anticipation of the virus' activation.
Upon activation, the virus performs a so-called denial-of-service attack, in which machines infected with the virus continually send bogus Web traffic requests to the RIAA site, overwhelming it so it can't handle legitimate requests.
"It's impossible to filter the traffic because it looks identical to the same type of traffic generated by a regular browser," said Tony Magallanez, systems engineer at F-Secure Corp. in San Jose. "You get to a point where if enough machines become infected it can overwhelm pretty much any connection."
Sites targeted in the past include those of Microsoft Corp. and anti-spam organizations.
The RIAA site has been attacked several times since July 2002. As the trade organization for the major recording label, the RIAA has been at the forefront of efforts to stop file-sharing programs.
If the "MyDoom.F" virus had caused the five-day jam, it suggests tens of thousands of computers have been infected, Gullotto said.
So far, both McAfee and F-Secure have seen the virus crop up mostly on computers in Europe, but it remains a low priority compared to other, more prolific computer viruses.
"It's not on our immediate radar," Gullotto said. "It's fallen far enough on our top 10 or even top 100 in the last week."