Removed APK files are infected while developers are creating these apps in compromised windows platform where attackers infect the applications with Windows-based keylogger.
These types of attacks are targeting the software supply chain which means that, trusted compromised platform used for carries the infection to other platforms.
These infected apps are being in the Google Play store for almost 6 months and most the apps are released in the Google Play store between October 2017 and November 2017.
All among the removed infected apps have more than 1,000 installations and 4-star ratings and all the apps are not belongs to a single developer.
According to paloalto networks researchers, Most of the infected apps are include “Learn to Draw Clothing”, an app teaching people how to draw and design clothing; “Modification Trail”, an app showing images of trail bike modification ideas; “Gymnastics Training Tutorial”, an app letting people find healthy ideas for gymnastic moves.”
How Does this Malware infection Work
Researchers identified different malicious PE files that infected different apps and there are 2 main PE files that infect many of the removed apps.
Apart from this, researchers identified several malicious PE files and these infection files indicate that developers used machines are having a serious infection.
All among the removed malicious apps, there is one common malicious PE files that infect almost all the Android apps which carry windows Keylogger.
“These files fake their names to make their appearance look legitimate. Such names include “Android.exe”, “my music.exe”, “COPY_DOKKEP.exe”, “js.exe”, “gallery.exe”, “images.exe”, “msn.exe” and “css.exe”.”
Also, it contains other malicious activities such as attempts to sleep for a long period, Changes Windows registry, Creates executable and hidden files.
“The Windows Malware cannot directly run on the Android hosts. However, if the APK file is unpacked on a Windows machine and the PE files are accidentally executed, or the developers also issue Windows-based software, or if the developers are infected with malicious files runnable on Android platforms, the situation will go much worse, researchers said.”
All the infected apps have been reported to the Google Security Team and all infected apps have been removed from Google Play.