The number of threats targeting mobile devices has rapidly increased in the past couple of years and according to Fortinet, most such malware originates in Russia and China.

Based on statistics compiled by the security vendor, mobile malware families that have a monetary goal are by far the most common type, accounting for 60% of all threats in 2010.

The company also notes that no new annoyware, the previous leading mobile malware category, has been created after 2009.

Another interesting find when analyzing mobile threats was that most were developed in Russia and China. More precisely, 33% of malware families are of Russian origin and 20% are Chinese.

"We usually attribute a given family to a country when we spot several indications leading to the same country: function names written in Russian, phone numbers with Russia’s international prefix etc.," explains Axelle Apvrille, senior antivirus analyst at Fortinet.

However, the researcher warns that determining malware origin is always uncertain, because even strong clues can be intentionally planted in the malware.

Nevertheless, these findings reflect the trend noticed during the last two years, when most threats, be them click fraud trojans, credit stealers or spyware, were Russian or Chinese.

Despite a rapid growth of Android malware seen recently by security vendors, Symbian remains the most targeted mobile operating system. "Over 50% of mobile malware families Fortinet detects concern Symbian, approximately 15% are Java ME midlets," Apvrille says.

It's not a surprise that most mobile threats come from Russia and China. Those countries have very large markets and mobile piracy is pretty high. That means users are used with downloading mobile applications from warez websites or unofficial app stores and cybercriminals are always ready to take advantage of that.

Running a mobile antivirus program is becoming increasingly necessary and some vendors have even started offering free solutions.