A worrying trend: Attacks are increasingly targeted at executives due to the valuable data they're carrying on their phones. Using a combination of SMS and social engineering tactics, hackers can spoof the phone number of a friend or a colleague to send an SMS asking the victim to click on a suspicious link, opening up the phone to attack.

To prevent malware spreading the mobile operating systems are pursuing a number of approaches. and BlackBerry, for example, have introduced security protocols in tandem with a meticulous acceptance process for apps offered via their stores.

The picture is less tidy for . Perhaps because it currently has the highest market share, Android provides attractive returns for criminals. Another theory is that due to the openness of the platform and the existence of other markets from which to download apps, it's easier to infiltrate. Whatever the reason, the stark reality is that it .

That said, as market share shifts and rogue programmers perfect their code, it would be foolish to think that any particular operating system will remain infallible indefinitely.

The best way to fight mobile malware is to defend against incursion, and in this everyone has a function to perform. As they're on the front line, phone users themselves must understand the risks, and the criminals' tactics, if they're to practice safe phone use: