Banking malware and "backdoor" Trojans, which steal data from a computer without the victim realizing it, were the most popular mobile threats unleashed during the second quarter, according to a report released this week by McAfee Labs. The company found more than 17,000 new strains of malware targeting Android devices during the three-month period — a 35% growth rate, higher than any the company has seen since 2010. All told, McAfee now counts 147 million types of malware in its database.

In one example, the company found four pieces of mobile malware that capture a bank customer's user name and password and intercept SMS messages the bank sends to the customer for authentication. The malicious parties then directly access the account and transfer funds.

The security software company also found that banks and online auctions are the biggest targets of phishing.

Among other growing threats described in the report, McAfee researchers saw an increase in suspicious URLs in the second quarter (such fake websites act as distribution mechanisms for malware). At June's end, the total number of suspect URLs tallied by McAfee Labs reached 74.7 million, which represents a 16 percent increase over the first quarter.