ESET, dedicated to developing high-performing security solutions for home users and corporate customers, detecting and disabling all known and emerging forms of malware, has warned that common occurrence in recent times has been the emergence of malicious apps in the official iOS and Android app repositories.

The Company described the phenomenon as first seemed extremely rare but that has unfortunately become more common over time.

This trend has even affected the Apple App Store, which theoretically has more controls than the Google Play Store for Android, Denise Giusto Bilić, ESET Security Researcher, said in a 2017 IT security trends report released by the company recently.

Bilić identified that as for publishing applications, numerous factors encourage the existence of malicious apps in Google’s app store.

According to her, not only is Android a favorite target for cybercriminals because it has the largest number of potential victims, but the speed at which apps are published on the Play Store also makes it a potential target for many attackers trying to propagate their threats.

She said, “With Android, any developer can create an account with a one-off payment of USD 25, upload an application, and have it published within 24 hours. In contrast, the cost of iOS development membership is more than USD 99 per year and the app approval waiting period can last weeks.

“So while improvements to Bouncer (Google’s module for automatic analysis and malware detection) are made on a regular basis, and manual code analysis is being strengthened, the huge number of new apps that are created daily and the haste with which they are incorporated into the market makes accurate analysis of each one difficult”.

Bilić added that it is possible that in order to reduce future cases of malware introduced into its official app store, Google will need to modify one of these variables—or both—to devote more resources to intensive analysis of a reduced number of applications and/or extend the time needed for the approval process, undermining the speed of publication.

“One of the several strategies Google might use to reduce the number of candidate applications could be raising the price for developers' accounts.

“What is certain is that so long as the policy framework for publication in the Play Store remains unchanged and none of these corrective measures are taken, we can expect to see a greater amount of malware in official stores in 2017 as attackers double down on this new modus operandi and find new mechanisms to evade detection.

“With regard to this last point, it should be noted that there are many techniques that render mobile malware detection difficult: time bombs, dynamic code executed through reflection, packers, encryption, obfuscated strings, scripts in other programming languages for remote downloading of malicious code, new forms of C&C, anti-emulation, rootkits, etc.

“But above all, cybercriminals are betting and will continue to bet on social engineering, waiting attentively for the official launch of popular apps to distribute their own fake versions, as happened recently with Pokémon GO, Prisma and Dubsmash.

“The speed with which these malicious applications rack up hundreds and even thousands of downloads is a cause for concern among users of the platform. What will happen when cybercriminals decide to greatly increase the complexity of their creations? Users' different approaches with respect to the installation of applications also plays counterproductive role when it comes to Android”.

Bilić emphasized that the ease with which someone can modify an APK obtained from the official store in order to inject malicious code and distribute it through websites or fake app stores, added to the ease with which users install files from untrustworthy sources, results in a higher rate of malware detection (and in the worst case, infestation) compared to other mobile operating systems.