SMS stealing apps uploaded to Google Play by Carberp banking malware gang

The apps were designed to steal mobile transaction authentication numbers from Russian online banking users, Kaspersky Lab says

Several malicious Android apps designed to steal mobile transaction authentication numbers (mTANs) sent by banks to their customers over SMS (Short Message Service) were found on Google Play by researchers from antivirus vendor Kaspersky Lab.

The apps were created by a gang that uses a variant of the Carberp banking malware to target the customers of several Russian banks, Denis Maslennikov, a senior malware analyst at Kaspersky, said Friday in a blog post.

Many banks use mTANs as a security mechanism to prevent cybercriminals from transferring money from compromised online banking accounts. When a transaction is initiated from an online banking account, the bank sends an unique code called an mTAN via SMS to the account owner's phone number. The account owner has to input that code back into the online banking website in order for the transaction to be authorized.

In order to defeat this type of defense, cybercriminals created malicious mobile apps that automatically hide SMS messages received from numbers associated with the targeted banks and silently upload the messages back to their servers. Victims are tricked into downloading and installing these apps on their phones via rogue messages displayed when visiting their bank's website from an infected computer.

SMS stealing apps have previously been used together with the Zeus and SpyEye banking Trojan programs and are known as Zeus-in-the-Mobile (ZitMo) and SpyEye-in-the-Mobile (SpitMo) components. However, this is the first time a rogue mobile component designed specifically for the Carberp malware has been found, Maslennikov said.

Unlike Zeus and SpyEye, the Carberp Trojan program is primarily used to target online banking customers from Russia and other Russian-speaking countries like Ukraine, Belarus or Kazakhstan.

According to a report in July from antivirus vendor ESET, Russian authorities arrested the people behind the three largest Carberp operations. However, the malware continues to be used by other gangs and is being sold on the underground market for prices between US$5,000 and $40,000, depending on the version and its features.

"This is the first time we've seen mobile malicious components from a Carberp gang," Aleksandr Matrosov, senior malware researcher at antivirus vendor ESET, said Friday via email. "Mobile components are used only by one Carberp group, but we can't disclose more details at the present."

The new Carberp-in-the-Mobile (CitMo) apps found on Google Play masqueraded as mobile applications from Sberbank and Alfa-Bank, two of Russia's largest banks, and VKontakte, the most popular online social networking service in Russia, Maslennikov said. Kaspersky contacted Google on Wednesday and all CitMo variants were deleted from the market by Thursday, he said.

However, the fact that cybercriminals managed to upload these apps to Google Play in the first place raises questions about the efficiency of the app market's anti-malware defenses, such as the Bouncer anti-malware scanner announced by Google earlier this year.

"It seems that it's not that hard to bypass Google Play's defenses because malware continues to appear there regularly," Maslennikov said via email.

Bogdan Botezatu, a senior e-threat analyst at antivirus vendor Bitdefender, believes that it might be hard for Google's Bouncer to detect ZitMo, SpitMo or CitMo components because they are functionally similar to some legitimate applications.

"The mobile version of the Trojan is only responsible with hijacking the received SMS and forwarding its contents to a different recipient, and this behavior is also found in legitimate applications, such as SMS management apps or even applications that allow the user to remotely control their devices via SMS in the event they get stolen or lost," he said via email. "SMS interception is a feature that is well documented on forums, along with sample code. If the same sample code is used both in malicious and legit applications, it would be even harder to detect and block."

The ability to use Google Play to distribute SMS stealing apps offers advantages to cybercriminals, Botezatu said. First of all, some user devices are configured to only install apps obtained from Google Play. Also, users are generally less suspicious of apps downloaded via Google Play and pay less attention to their permissions because they expect the applications to be what their descriptions claim they are, he said.

Join the Good Gear Guide newsletter!

Error: Please check your email address.

Tags securitymobile securityscamsspywareesetmalwarebitdefenderkaspersky labfraud

Our Back to Business guide highlights the best products for you to boost your productivity at home, on the road, at the office, or in the classroom.

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Lucian Constantin

IDG News Service
Show Comments

Essentials

Microsoft L5V-00027 Sculpt Ergonomic Keyboard Desktop

Learn more >

Lexar® JumpDrive® S57 USB 3.0 flash drive

Learn more >

Mobile

Lexar® JumpDrive® S45 USB 3.0 flash drive 

Learn more >

Exec

HD Pan/Tilt Wi-Fi Camera with Night Vision NC450

Learn more >

Lexar® Professional 1800x microSDHC™/microSDXC™ UHS-II cards 

Learn more >

Audio-Technica ATH-ANC70 Noise Cancelling Headphones

Learn more >

Lexar® JumpDrive® C20c USB Type-C flash drive 

Learn more >

Budget

Back To Business Guide

Click for more ›

Most Popular Reviews

Latest News Articles

Resources

PCW Evaluation Team

Michael Hargreaves

Windows 10 for Business / Dell XPS 13

I’d happily recommend this touchscreen laptop and Windows 10 as a great way to get serious work done at a desk or on the road.

Aysha Strobbe

Windows 10 / HP Spectre x360

Ultimately, I think the Windows 10 environment is excellent for me as it caters for so many different uses. The inclusion of the Xbox app is also great for when you need some downtime too!

Mark Escubio

Windows 10 / Lenovo Yoga 910

For me, the Xbox Play Anywhere is a great new feature as it allows you to play your current Xbox games with higher resolutions and better graphics without forking out extra cash for another copy. Although available titles are still scarce, but I’m sure it will grow in time.

Kathy Cassidy

STYLISTIC Q702

First impression on unpacking the Q702 test unit was the solid feel and clean, minimalist styling.

Anthony Grifoni

STYLISTIC Q572

For work use, Microsoft Word and Excel programs pre-installed on the device are adequate for preparing short documents.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?