Viruses aren't just for desktops and mobile platforms, such as the Palm OS and Windows Mobile, which got their start in PDAs, anymore. Russian antvirus company Kaspersky Labs is reporting the discovery of the first worm designed to infect and be progogated by Symbian OS smartphones. Kaspersky, which named the worm Cabir, said it is also the first network worm that propagates via mobile networks.

Kaspersky's preliminary analysis of the malicious code shows that that Cabir is transmitted as an SIS file (a Symbian distribution file), but the file is disguised as Caribe Security Manager utility, part of the smartphone's security software. It does this so, like with many desktop viruses, Symbian OS smartphone owners will launch the infected file, for example, from an email attachment. (One way around getting infected by a virus on any computer, mobile or otherwise, is not to launch attachments, especially form those you don’t know, from within your e-mail's inbox.)

When launched, the worm makes the smartphone's screen display the inscription "Caribe". The worm then penetrates the system and will then be activated each time the phone is started. Cabir also scans for all accessible phones using Bluetooth technology, and sends a copy of itself to the first one found.

According to Kaspersky, the worm was created by a virus writer going under the name of Vallez. This pseudonym is used by 29a, an international group of virus writers. The group specializes in creating proof-of-concept viruses. Among the group's creations are Cap, the first macro virus to cause a global epidemic; Stream, the first virus for additional NTFS streams; Donut, the first virus for .NET and Rugrat, the first Win64 virus.

Fortunately, Kaspersky's analysis of the worm's code has not so far detected any malicious payload. In addition, though the worm is coded to run under the Symbian OS used in many Nokia telephones, it is possible that Cabir will function on handsets produced by other manufacturers.

Kaspersky didn't offer any instructions on how to remove the worm. However, users can take precautions, such as the one listed above about e-mail and attachments, as well as setting the Bluetooth function of their device so it only works with other specific devices. That way, other users can’t, unknown to them, randomly discover your smartphone.

By picking the Symbian OS, the Cabir writers have chosen the most commonly used platform for smartphones to demonstrate their “proof of concept”. Global shipments of handsets based on the Symbian platform doubled to 2.4 million in the first quarter of this year over the first quarter of 2003.

The latest version of Symbian OS, version 8.0, already released to licensees, aims to enable the accelerated development of lower cost Symbian OS phones, enhanced device management, multimedia and Java capabilities

According to Gartner, in 2003, more than 6.67 million smartphones based on Symbian OS were shipped worldwide. There were a total of about 10 million smartphones sold, which takes into consideration Symbian, Windows Mobile, the Palm OS and Linux. While this is a drop in the bucket compared to the over 520 million mobile phones sold worldwide last year, the overall sales of smartphones are expected to grow exponentially over the next few years. ABI Research predicts Symbian will ship on almost a quarter of all handsets by 2009. That's in a market that should top 600 million units.

Most Symbian-based smartphones, including Nokia's own products, use that company's Series 60's platform. Five (Lenovo, Siemens, Samsung, Panasonic, Sendo and Nokia) licensees have announced devices with the Series 60 interface. In addition, more than 100 operators are now selling handsets based on the Series 60 Platform, including all the major GSM operators in the US & Canada.