​Moscow, March 3 (IANS) Last year saw a near-threefold rise in mobile malware detections as compared to 2015, with 8.5 million malicious installations being identified and advertising Trojans leading the way, a new report said on Friday.

According to a report by the Russian cyber security company Kaspersky Lab, in the space of just one year, a volume equivalent to 50 per cent of all the malware detected in the previous 11 years (15.77 million from 2004-2015) was released.

Advertising Trojans now make up 16 of the top 20 malicious programmes -- up from 12 in 2015, said Kaspersky Lab's annual 'Mobile Virusology' report.

"Throughout the year, advertising Trojans were the top threat and we see no sign of this trend changing. Cyber criminals are taking advantage of the fact that most devices do not receive OS updates (or receive them late) and are vulnerable to old and readily available exploits," said Roman Unuchek, Senior Malware Analyst at Kaspersky Lab US.

The report found that nearly 40 million attacks were attempted by mobile malware and over four million users of Android-based devices were protected. More than 153,000 unique users were targeted by mobile ransomware.

"Trojans are capable of seizing rooting rights, allowing the malware to not only aggressively display ads on the infected device, often making it impossible to use, but also to secretly install other applications. These Trojans can also buy apps on Google Play," the report found.

In 2016, over 305,000 users in 164 countries were attacked by mobile banking Trojans, compared with over 56,000 users in 137 countries in 2015.

Russia, Australia and Ukraine are the top three countries affected in terms of the percentage of users attacked by mobile banking Trojans relative to all users hit by mobile malware.