More than 40,000 websites have fallen victim to a virus attack that is still growing, security experts have said.
Security firm Websense says the site beladen.net is infecting legitimate websites all over the world with malicious code that then tries to install malware on the computers of people visiting them.
The Beladen virus is still active, with the number of affected sites growing from 20,000 to over 40,000 since Friday.
Carl Leonard, security research manager for EMEA at Websense, said the Beladen virus poses a "pretty serious" threat to users.
"We are trying to look into how these sites are compromised in the first place," he said. Anti-virus detection capability is also not that high, with 13 out of 40 systems tested by Websense failing to detect the malware.
The malware could be stealing data, but it is not yet clear what it does to computers. It is also targeting a wide range of websites with a multiple types of content. "Any user in any country could potentially stumble upon an infected site," said Leonard. "Users need solutions that they know will protect them against this."
The attack is similar to the Gumblar virus, but is separate and distinct. It is also similar to attacks from the Russian Business Network, Websense says.