A new virus is making the rounds that forces some cell phones based on the Symbian operating system to generate pricy text messages.
The virus is within an illegal version of the cell phone game Mosquito that is now available for free on the Internet and peer-to-peer networks, according to a statement from Symbian, the company that licenses the operating system of the same name.
Once installed, the game may cause phones to send text messages to premium rate numbers in the United Kingdom, Germany, the Netherlands and Switzerland without the user's approval or knowledge, Symbian said. Deleting the game rids users of the problem, the company said.
"The Mosquito Trojan is a clear indication that users need to be aware of the risks of downloading and installing illegal or pirated software," Symbian said. "Symbian believes that mobile security is the responsibility of the entire industry. It requires cooperation and trust."
The company did not offer an estimate of the number of phones affected nor when the virus began making the rounds.
The latest episode underscores how virus writers are now focusing on smart phones, which are cell phones always connected to the Internet and PDA-like processing power for much more complex tasks than a typical handset. The two major smart phone operating system makers are Symbian and Microsoft.
The Mosquito Trojan comes about a month after antivirus companies began deciphering the workings of the first worm to target smart phones. That worm program, dubbed Cabir by Russian antivirus company Kaspersky, apparently uses the Bluetooth short-range wireless feature of smart phones that run the Symbian operating system to detect other Symbian phones, and then transfers itself to the new host as a package file. While able to replicate the spread of the virus in research settings, antivirus companies have not found any evidence that the program is infecting smart phones outside of those limited test cases.
In mid-July, a virus that infects Windows CE was developed--the first such bug discovered for the handheld operating system, according to one firm. Romania-based BitDefender said it has discovered a "proof of concept" virus for Microsoft's operating system for smart phones and other handhelds. The malicious code's author, who uses the pseudonym Ratter, is part of the 29A VX group that created a virus for the Symbian OS.