Description

As per reports, four different Android banking trojans such as Anatsa (aka TeaBot), ERMAC, Hydra, and Alien were distributed through the official Google Play Store between August and November 2021, infecting over 300,000 devices using various dropper programs that appear as benign apps. These trojans are said to be constructed with minimal harmful footprints to ensure that payloads are downloaded on Android smartphones from certain countries and steals user passwords, keystrokes, SMS-based two-factor authentication tokens, and screenshots after installing on the victim's device. These Malwares allegedly used a technique known as versioning, in which it first installs harmless software before dropping hazardous functions as part of app upgrades with its C2 server theme, which is also designed in the style of dropper applications. Anatsa, a banking trojan, has been deployed over 100,000 times as QR code scanners, PDF scanners, and cryptocurrency programs. After users install the app, the infection chain process begins by pushing them to upgrade the app to continue; during the app update, Anatsa malware is downloaded from a remote server. It obtains complete control of an infected device after enabling Accessibility Service. Moreover, a threat actor dubbed Brunhilda disseminated Vultur, a remote access trojan that masquerades as QR code maker apps and drops trojans such as Hydra and ERMAC on victims' PCs. Similarly, "Gymdrop," a fitness-themed dropper, has been installed over 10,000 times. When it is installed, it is given a configuration file that instructs it to download the Alien banking trojan payload from the C2 server. According to the researchers, since the malware developers manually initiate the installation of a banking trojan, it is trickier to detect and more difficult for automatic detection.