New Android Trojan Ad Library Called “Zavier”  Infected more Than 800 Android Apps which is Estimated around more than million downloads in Google Play and distributed over a large number of people around the Globe.

Zavier Malwre Detected as “ANDROIDOS_XAVIER.AXM” that silently infect and steal the users information and leak the personal information.

This Malicious Ad Library Uses Remote server to Download codes that contain embedded Malicious Behavior loads into the infected Malware apps in Android phone.

Also Read Malicious Android ads leads to Automatically Download and Install Apps that Contain Malware in Android Devices

Embedded Xavier ad library in Google Playstore{Image Credit :Trend Micro}

Its seems More evasive to being Detected by the Traditional Detection method which including String encryption, Internet data encryption, and emulator detection.

Maximum number of Downloads has been discover in Asian  Countries such as Vietnam, Philippines, and Indonesia, with fewer downloads from the United States and Europe.

Stealing and leaking capabilities

According to the Trend Micro Research , This Malware Manipulate the users data including photo manipulators to wallpaper and ring tone changers..

Zavier’s Sophisticated  self protecting Mechanism helps to avoid Detection by both static and Dynamic analysis.

“Xavier also has the capability to download and execute other malicious codes, which might be an even more dangerous aspect of the malware. Xavier’s behavior depends on the downloaded codes and the URL of codes, which are configured by the remote server.”

Xavier malware Variant Initially identified in earlier of 2015 and it was infected millions of devices that has 2,000 apps with similar behavior on Google Play.

Evalution of Xavier {Image Credit :Trend Micro}

First Version of Xavier Malware Ad library called joymobile had Remote code execution functionality that was Discovered on 2015 .

This ad library is capable of installing other APKs, and it can do this silently if the device is rooted.


Malware Authors using Command & Communication Server (C&C Server) for further communication for steal the information and specifically used without any encryption but   constant strings were encrypted in the code.

Also Read  A Banking Trojan Called “QakBot ” Attack Thousands of Windows Active Directory and users to get locksout of their Company’s Domain

Xavier Used 4 ways to Avoid Detection

According to Trend Micro Report ,

1) It encrypts all constant strings, making static detection and manual analysis more difficult.

2) It performs net transmission via HTTPS to prevent its traffic from being caught. The data is also encrypted

3) It uses a wide array of reflection invoking methods, with the the class name and method name being encrypted

4) It will hide its behavior based on the running environment.

To Read Full Technical analysis Visit Trend Macro

Also Read Beware: New Google Play Store Android Malware called “Judy” Infected Around 8.5 to 36.5 Million Users

BALAJI is an Ex-Security Researcher (Threat Research Labs) at Comodo Cybersecurity. Editor-in-Chief & Co-Founder - Cyber Security News & GBHackers On Security.


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