They work their way through your phone book, your inbound and outbound calls, and then infect all those numbers. They slow down or cripple your phone. These days, mobile software viruses are not only nastier than ever, they're prevalent. In fact, there are about 400 different types lurking out there. Mobile phone viruses are becoming increasingly sophisticated and malicious in their activities.

Phones using the Symbian operating system such as certain models from -Nokia and Samsung, or which run on Windows Mobile and Pocket PC-based applications, are most susceptible.

The mobile security provider also says hand phone users in the Asia-Pacific region are some of the worst affected in the world, with many users receiving up to 10 mobile spam messages a day.

• Watch that download. Virus writers may create viruses masquerading as the latest song, video clip or wallpaper. Make sure you download from reliable sites.
• Delete suspicious messages. Applications sent via Bluetooth, SKIS or MMS make your phone vulnerable to viruses. Reject and immediately delete messages that look as suspicious as spam e-mail: gobbledygook text made up of letters and characters. Unless you have an admirer who's very forward, ignore and delete messages with suspect subjects like "sexy fancy me?"
• Check your credit. If it is running out faster than expected, your load is possibly being eaten up by a virus that sends multiple copies of the same message to your contacts without your initiation.

So install mobile anti-virus solutions

• Switch off your Bluetooth. Viruses use it to "travel". Switch to undiscoverable mode for protection.
• Don't "talk" to strangers. A harmless "message" informs you of a "voicemail". You must call a certain number to retrieve it but there'll be no voicemail and you'll be charged a premium rate for making that call. The main aim of spam in the mobile space is to "steal money off you.
• Don't click on that link. Mobile spam is used to solicit your private information. You might, for example, be asked to click on a link and provide personal details for free music. Usually-, there'll be nothing in it, except a case of identity theft and more spam. Spammers also send messages from the "bank" to solicit sensitive information. So, always double-check on the source of unsolicited messages.