Cyber criminals are becoming even more aggressive and are using new stealth techniques.
Security experts at Kaspersky have discovered that one of the most dangerous Android banking Trojan, Svpeng, has been recently modified to implement keylogger features to improve data stealing capabilities.
Kaspersky Lab spotted a new variant of Svpeng a couple of weeks ago with a new keylogger feature, which takes advantage of Android’s Accessibility Services.
“In mid-July 2017, we found a new modification of the well-known mobile banking malware family Svpeng – Trojan-Banker.AndroidOS.Svpeng.ae. In this modification, the cybercriminals have added new functionality: it now also works as a keylogger, stealing entered text through the use of accessibility services.” reads the analysis published by Kaspersky.
The Accessibility Services is an Android feature that provides user interface (UI) enhancements for users with disabilities or those temporarily unable to interact with a device.
This new feature allows the Svpeng Trojan to log all keystrokes on the device and to get the malware obtaining more permissions and rights to prevent victims from uninstalling it.
In November 2016 the number of Android devices infected with the Svpeng banking trojan was more than 318,000 worldwide. Crooks exploited a Chrome Zero-Day vulnerability to deliver the Android Svpeng Trojan to Android users via Google AdSense.
In May, malware researchers discovered another attack technique dubbed Cloak and Dagger attack that exploit the Android’s Accessibility Services to silently take full control of the infected devices.
The new strain of the Svpeng Trojan has already infected devices in 23 countries, including Russia (29%), Germany (27%), Turkey (15%), Poland (6%) and France (3%).
The malware researchers noticed that the malware doesn’t perform malicious actions on devices belonging to Russian users.
The Svpeng Trojan distinguish Russian users by checking the device’s language. If the language is Russian, the malware doesn’t perform further malicious tasks.
This circumstance suggests the gang behind the threat is Russian.
The latest variant of the Svpeng discovered in July was being distributed through malicious websites that disguised as a fake Flash Player.
Once installed, the malware asks the device to use Accessibility Services that allows it grants itself device administrator rights, displays an overlay on the top of legitimate apps. The malware is also able to grant itself some dynamic permissions, such as the ability to make calls, send and receive SMS, and access the victim’s contacts.
“Using accessibility services allows the Trojan to get access to the UI of other apps and to steal data from them, such as the names of the interface elements and their content, if it is available. This includes entered text. Furthermore, it takes screenshots every time the user presses a button on the keyboard, and uploads them to the malicious server. It supports not only the standard Android keyboard but also a few third-party keyboards.” states Kaspersky.
“Some apps, mainly banking ones, do not allow screenshots to be taken when they are on top. In such cases, the Trojan has another option to steal data – it draws its phishing window over the attacked app. It is interesting that, in order to find out which app is on top, it uses accessibility services too.”
The researchers intercepted an encrypted configuration file from the malware’s C&C server, the analysis of the file allowed them to identify other apps targeted by the Svpeng Trojan along with phishing URLs to overlay them.
The config file decrypted by the experts contained a phishing URL for the PayPal and eBay mobile apps to steal credentials and URLs for banking apps from different countries:
The file also allows the malware to receive various commands from the C&C server, including instructions:
(Security Affairs – Svpeng Trojan, Android malware)