'Joker' Malware Capable Of Signing Victims Up For Subscription Services Discovered In Google Play Apps

A new malware program called “Joker” has been discovered in 24 apps on the Google Play store.

The malware was discovered by cybersecurity firm CSIS, which first reported about the virus on Tuesday. CSIS describes it as a program designed to deliver a “second stage component” that will steal the victim’s personal contact and device information. It also “silently simulates the interaction” with websites that could see the victim unknowingly signed up for subscription services.

Aleksejs Kuprins, a malware analyst at CSIS, wrote: "This strategy works by automating the necessary interaction with the premium offer’s webpage, entering the operator’s offer code, then waiting for an SMS message with a confirmation code and extracting it using regular expressions. Finally, the Joker submits the extracted code to the offer’s webpage, in order to authorize the premium subscription."

It can also be easy to miss since it’s designed to make “as little footprint as possible.” This is accomplished by “Joker” using as little Java code so it can remain unnoticed.

Google removed the 24 apps after learning about the malware, however, they did accrue 472,000 downloads before being removed. A majority of these downloads have been linked to the U.S., Europe and Southeast Asia.

Kuprins further explains that the virus is programmed to attack “targeted countries.” This is done thanks to the Mobile Country Codes, or MCCs, that are programmed into the apps. The victim’s active SIM card will then allow “Joker” to be properly delivered after the app is downloaded.

“Joker” will then operate in the device’s background until it receives an SMS message. It also knows when to contact a premium advertisement, automatically signing the victim up for said service.

Below are the apps infected with the “Joker” malware.

Advocate Wallpaper

Age Face

Altar Message

Antivirus Security - Security Scan

Beach Camera

Board picture editing

Certain Wallpaper

Climate SMS

Collate Face Scanner

Cute Camera

Dazzle Wallpaper