TrustGo Mobile said the virus Trojan!MMarketPay.A@Android is targeting China Mobiles' Mobile Market. With more than 600 million users, China Mobile is one of the largest wireless providers in the world. The virus automatically places orders and downloads paid apps and video content, driving up its victims' phone bills.

Since the Trojan!MMarketPay.A@Android malware was discovered on July 4, the virus has been found in nine additional China Android markets and has infected more than 100,000 devices, according to TrustGo Mobile.

Cloning Popular Apps

The majority of mobile malware is found in applications that originate from and attack third-party markets in China and Russia, the firm reports. The main source of Android-specific malware is the cloning, repackaging and modification of popular apps with intentionally malicious code.

"The ease and speed that malicious apps can be developed and distributed to unsuspecting users is one of the fastest growing security concerns," said Xuyang Li, CEO of TrustGo. "Anyone with a smartphone or mobile device is a potential target."

Neil Roiter, research director at Corero Network Security, said malicious mobile applications that covertly charge users for premium services, such as the new applications that are infecting thousands of Android devices in China, were becoming an increasing problem.

"It is essential that people download applications only from authorized Android application stores and do some research online before they download anything," Roiter said. "It's also a good idea to check your phone bill for unusual charges to ensure that that you are not paying for services that you didn't subscribe to."

Infiltrating Apple's Walled Garden

Meanwhile, Kaspersky Lab said MegaFon, a major mobile carrier in Russia, contacted the security firm about a suspicious application found in both the Apple App Store and Google Play. Kaspersky Lab expert Denis Maslennikov said it seemed to be an SMS worm spread via sending short messages to all contacts stored in a phone book with the URL to itself, at first glance.

However, the firm's analysis of the iOS and Android versions of the same application showed that it's not an SMS worm but a Trojan that uploads a user's phonebook to a remote server. Maslennikov explained in a blog post that the 'replication' part is done by the server -- SMS spam messages with the URL to the application are being sent from the remote server to all the contacts in the user's address book. The app is called "Find and Call."

"User will be able to continue using the application but at the same time the application steals data from the device (phone book and cell phone numbers) which are uploaded to a remote server to be used for SMS spam campaigns," Maslennikov wrote.

"Each phone book entry will receive SMS spam message offering to click on the URL and download this 'Find and Call' application. It is worth mentioning that the 'from' field contains the user's cell phone number. In other words, people will receive an SMS spam message from a trusted source."

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