Mobile viruses that infect your phone, delete applications, steal data, spy on you, and generally cause havoc, are spreading fast. Damage is being done on every high street in the UK as unsuspecting mobile users receive malicious malware beamed to their phones via Bluetooth.

Smartphones are the prime target of this mobile generation malware. Owing to the phenomenal success of Nokia in particular at spreading the use of Symbian S60-powered smartphones (such as the Nokia N73, N70, N95 and many more) into the mainstream, many phone users may be unaware quite how sophisticated - and therefore vulnerable to attack- their mobiles can be. Malware can infect phones by opening files sent via Bluetooth or email attachments and even MMS.

Since 2003, over 7.3 million smartphones have been sold in the UK and worldwide some 126 million Symbian smartphones are in circulation. And there are now believed to be over 300 smartphone viruses in the wild.

To highlight the growing danger, mobile anti-virus specialist UMU has alerted Tech.co.uk to what it considers the five worst mobile viruses affecting Symbian S60 phones currently in circulation...

Ultra-malicious

"The new breed of viruses are the most malicious we have ever seen," Peter Harrison, CTO, UMU said. "They are built by highly organised criminals, intent on either causing widespread damage or extracting maximum commercial gain. What is really scary is that lots of people may already be infected and not know it."

  • Cabir - spread via Bluetooth and MMS, it does not directly damage the phone but continually tries to detect other devices to infect, greatly reducing battery life. Cabir was the first known mobile worm to successfully spread through Bluetooth networks. (Virus origin - France)
  • CommWarrior - CommWarrier resets the phone on 14th of every month deleting all personal data. The virus spreads using Bluetooth and MMS utilising your phonebook contacts to send the MMS to. CommWarrior is the first known mobile malware that spreads via both Bluetooth and MMS. It can also be downloaded from malicious web sites as an archive file named COMMWARRIOR.ZIP. (Virus origin - Russia)
  • Skulls -Skulls is a highly destructive mobile Trojan program. It may arrive on a phone disguised as an installer for normal applications or theme packages. It disables programs and applications, such as the phone book, the SMS and MMS viewers and the music player on your phone preventing you from using them. It also changes all your icons to a skull and crossbones or a jigsaw piece. (Virus origin - Turkey)
  • CardTrap - CardTrap is the first known mobile malware that attempts a cross-platform infection by jumping from an infected phone to a target computer. It overwrites applications such as the phone book with corrupted copies. These applications will no longer work when you next reboot the phone, rendering the phone useless. It also drops installers for Skulls, CommWarrior and Cabir onto the device and puts some Windows viruses onto the memory card so that plugging the memory card into a PC will result in the PC being infected as well. (Virus origin - Turkey)
  • Doomed - This virus arrives disguised as an installer for a normal application. When run it stops normal applications on your phone from working, prevents your phone from restarting properly and introduces and runs all the other major viruses, including Skulls, CardTrap, CommWarrier and Cabir. The virus can also sometimes cause other Bluetooth devices in the vicinity of the infected one to restart. (Virus origin - Unknown)