Although mobile malware hasn't yet been blamed for any major data breach or cybercrime event, attackers are churning out a new piece of Android malware every 18 seconds -- and the rate is trending upwards.  

In the first quarter of 2015, 440,267 new samples of Android malware appeared, and the number may reach over 2 million by the end of the year, according to researchers at anti-virus firm G DATA, which just celebrated its 30th anniversary. That is a 6.4 percent increase over Q4 2014.

"The trend is heading upward," says Andy Hayter, Security Evangelist for G DATA. "Android [malware] is growing and Android [malware] is profitable."

Yet, according to the Verizon Data Breach Investigations Report, less than 0.03 percent of mobile devices are infected with "high-impact" malware each year, and mobile phones were not being used in remote attacks.

"We haven't seen the 'Melissa [virus]' for mobile malware yet," says Hayter. "That day will come. I predict sooner, than later. I think it's a matter of installed base and profit."

Hayter says that the use of premium SMS messages and mobile phone banking is not as high in the United States as it is in some other countries, so that may delay the explosion of Android malware used for financial gain. About half the samples (50.3 %) G DATA analyzed were financially motivated malware.

Globally, Android phones have a far higher market share than other smartphone platforms (78%, versus 18.3% for iOS, according to IDC), yet mobile devices have still been used less than desktop devices. That's shifting. According to G DATA's report, the global market share of Android smartphones and tablets used for Internet access exceeded 61 percent in the first quarter of 2015.

As for the malware itself, says Hayter, "It's sophisticated enough ... There are some stand-outs for uniqueness, but nothing that has spread widely yet."

The report outlines two financially motivated Trojans of note. The Svpeng Trojan combines the "functionality of a finance malware program with the potential of ransomware," according to the report. It can steal credentials or other access data when a banking app is used or it can encrypt the device. The Faketoken Trojan steals mTANs (transaction authentication numbers), which attackers can then use to transfer money to their own accounts. 

There's also plenty of cross-platform malware -- that can make the jump from a phone to a desktop client for example -- but nothing significant in number yet, says Hayter.

The concern is that when an Android malware strain really does try to hit hard, the users' devices won't be ready to defend themselves. Although there are anti-virus products out there for Android, Hayter says they aren't in very widespread use.

"Does everyone know they need anti-virus for their phone?" he says. "I don't think they know that yet."

He suggests Android users avoid malware, adware, and other potentially unwanted programs by only downloading from very trusted sources like the Google Play Store or your device manufacturer's store.