While the current generation of viruses for mobile phones are largely a theoretical problem, their rapid evolution means they will pose a major threat in the future, security experts have warned.
"What took 20 years to develop on the PC has taken about two years on mobile devices," David Emm, senior technology consultant for Kaspersky Lab, told a conference on business continuity in London recently.
"We have seen fully functional backdoor Trojans written for mobile devices. It's not the earth-shattering threat you might read about, but the threat is real."
The first mobile virus is generally considered to be Cabir, a proof-of-concept virus that spreads via Bluetooth and is designed to infect Symbian OS mobile phones.
Many variants of Cabir have been developed following the release of its source code, while other mobile viruses have been developed to perform operations such as sending text messages to premium-rate services, potentially creating a large phone bill and a lucrative source of revenue.
Now, mobile viruses account for a relatively small proportion of malware activity. Kaspersky currently identifies about 10 new mobile virus variants a week, which represents a tiny fraction of the 1400 or so pieces of malware it analyses in that period.
"The key here is going to be critical mass," Emm said.
As mobile phones become more capable and "smartphone" operating systems become the norm, it will be worthwhile for criminals to develop and modify mobile phone viruses, he predicted.
Earlier this month, Symbian CEO Nigel Clifford noted that smartphones were outselling portable music players, meaning such a situation is likely in the near future.
