The Google Play Store is seeing a wave of malware-infested apps like never before.
Four separate security companies have reported — or are preparing to release reports — on malware campaigns currently underway via Android apps available on the Play Store.
Reports published today by Dr.Web, Malwarebytes, and McAfee reveal the presence of three new Android malware families hidden in games and apps uploaded on the Play Store. An ESET spokesperson told the company also found a new multi-stage malware strain they're going to detail in a report later today. Based on the details included in the reports, the most complex and widespread threat is the Grabos malware found by McAfee researchers.
The McAfee team says it identified 144 Play Store apps containing this new threat, in most cases disguised as audio players and apps for downloading MP3 music files. Based on statistics from 34 of the 144 apps, McAfee says the malicious applications have been downloaded between 4.2 million and 17.4 million times.
Grabos' main purpose is to show fake notifications on infected devices that trick users into downloading and installing other apps. Based on its mode of operation, it is fair to believe the operators are using Grabos to gain revenue as part of a pay-per-app-install scheme.
For a deeper dive into Grabos modus operandi and its source code, check out the McAfee, which also contains a list of Play Store apps infected with this new malware threat.
AsiaHitGroup targets Asian users only
The second Android malware that came to light today was discovered by security researchers from Malwarebytes, which they named AsiaHitGroup because it uses an IP address blacklist to target only users in Asian countries.
AsiaHitGroup was initially found in a QR scanner app named "Qr code generator – Qr scanner" that was also available through the Play Store. On infected devices, the AsiaHitGroup malwarewould download second-stage threat — an SMS trojan — whose main functionality is to subscribe users to premium phone numbers via SMS.
Malwarebytes also said it found AsiaHitGroup in other apps besides the QR code scanner, such as an alarm clock app, a compass app, a photo editor app, an Internet speed test app, and a file explorer app, but the company did not reveal the apps' names, nor did it say if Google removed any of the malicious apps at the time of writing.
Android adware loads websites in hidden browser
A third campaign that impacted the official Google Play Store and that also came to light today was documented by Dr.Web. This campaign centered around an adware strain the company identified as Android.RemoteCode.106.origin.
Researchers found this trojan in nine Play Store apps that had between 2.37 million and 11.7 million downloads. After users installed any of the tainted apps, they would open a website in a hidden WebView (browser) component. This process artificially boosted a website's traffic numbers and helped some site operators make money from ad impressions.
Dr.Web said it informed Google of the malicious apps, and some (but not all) have updated their code to remove the malicious behavior. Dr.Web has a list of the nine apps in its report.
Three-stage Android malware hits Play Store
Similarly, ESET researchers also uncovered a fourth malware campaign on the Play Store. According to a report published today, ESET found eight apps infected with a multi-stage Android malware strain that used timed deployments and anti-detection features to stay under the radar and deliver the MazarBot banking trojan on infected devices.
Unlike the first three campaigns, this one affected only tens of thousands of users, mainly because it was caught in its incipient stages.
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