Smartphones have become prime targets for hackers and spammers, said McAfee in its Threats Report for the final three months of 2010.

The computer security company said malware increased 46% last year as compared with 2009.

McAfee has recorded the steady increase of software threats to mobile devices in recent years with increasing popularity of smartphones and tablet computers.

McAfee Labs senior vice president Vincent Weafer said cyber criminals are keeping tabs on what is popular, and what will have the biggest impact from the smallest effort.

Weafer added, "We’ve seen a significant shift in various regions, showing that cyber criminals are tapped in to trends worldwide."

"McAfee Labs also sees the direct correlation between device popularity and cybercriminal activity, a trend we expect to surge in 2011."

Cyber criminals seem to be targeting Google’s Android operating system and Apple’s iPhone in particular.

Hacker tactics include tricking people into downloading malware or revealing banking information with the help of apps. Hackers also use apps to spy on smartphone users and to record calls and text messages. Adobe software products were the clear choice of malware authors and cyber criminals, said McAfee.

It added Web-based threats will continue to grow in size and sophistication.