Researchers security they discovered another incident with me Android malware hidden in applications and registers unsuspecting users in premium services without knowing it. Her researchers Check Point they discovered that the famous Joker malware he found another trick to bypass his protections Google Play Store: hides the malicious DEX executable in the application as "Base64 encoded strings", which are then decoded and loaded into the compromised device.
Following the revelation of Check Point researchers, the 11 suspects applications removed from the Google Play Store on April 30, 2020.
“Joker malware is difficult to locate, despite the addition of additional levels protection in the Google Play Store, ”said Check Point Aviran Hazum, who identified the new Joker malware mode. "Although Google removed the malicious ones applications from the Play Store, we expect the Joker to adapt again ".
Joker malware was discovered in 2017 and is one of the most popular types of Android malware. It is known for committing fraud, the spyware its capabilities and theft of SMS messages, contact lists and information device.
The Joker infected a lot of Android applications in the previous year, which were discovered by CSIS Security Group, Trend Micro, Dr.Web and Kaspersky. The researchers found that malware was constantly finding ways to exploit vulnerabilities in Play Store security checks.
The creators of Joker malware have used various methods to hide the true nature of the applications and avoid detection.
"As the Play Store introduced new policies and Google Play Protect strengthened its defenses, the Joker applications began to look for new gaps. security", Said the Android security and privacy team. "They used almost every concealment technique in an attempt to hide them."
As of January 2020, Google has removed more than 1.700 Play Store apps over the past three years and infected them with malware.
The new variant of Joker malware detected by Check Point achieves its purposes by utilizing the manifest file of the application, which it uses to load one file DEX coded Base64.
A second "intermediate" version uses a similar technique to hide the .dex file.
"To enable users to sign up for premium services without their knowledge or consent, the Joker malware used two main elements - the Notification Listener as part of the original application and one dex file which is loaded by the C&C server to perform the registration ", said the researchers.
The latest version of the Joker reminds us that Android malware is constantly evolving, so we must always be on the lookout.