Within a year Cabir has infected 22 countries, but recent sightings of Commwarrior in the Middle-East and India are leading to suggestions it could spread even further.
"All these have been isolated cases. Nevertheless, this virus is in the wild. Commwarrior could potentially be much bigger trouble than Cabir," said Jarno Niemela, a virus researcher writing on Finnish antivirus firm F-Secure's weblog. "Via MMS it can jump from one country to another easily."
Unlike Cabir, which spreads via Bluetooth alone and therefore can only spread as quickly as a plane flies, Commwarrior can also spread via MMS messages.
Currently Commwarrior's progress is slowed by certain bugs, including the fact that, over Bluetooth, a lot of user interaction is required.
"We are likely to see variants that spread quickly," said Patrik Runald, senior technology consultant at F-Secure. "Commwarrior sleeps a lot, possibly because the virus writer wasn't creating it with malicious intention. What would be more effective is a worm that sends itself to every number in a user's address book every ten minutes."
Progress over MMS is also slowed by varying levels of access to the multimedia messaging format globally. In places such as France MMS is not automatically available – a user has to ask the network to switch it on – so usage of MMS messaging services is not as wide yet as it eventually may be.
But Runald believes it is only a matter of time before a more effective mobile virus appears.
"We will see it soon, for sure," he said.
Earlier this week SC reported an investigation into mobile phone viruses spreading to cars. After rigorous testing a Toyota Prius withstood Bluetooth viruses better than either a PC or mobile phone.