Even though Google scans the apps in its Play Store for viruses, even there malware can sneak into apps disguised as harmless. That has been going on for years . With much more reason, it is logical to think that in other APP Stores, with fewer resources than Google, we find apps with viruses. And this was already confirmed a few years ago by security firm Opswat. The latter mentioned that up to a third of the applications in Google Play-like Android stores (which were unfortunately not mentioned) could contain malware. This conclusion was based on the analysis of 12,000 applications downloaded from alternative App Stores to the Play Store, whose Metascan antivirus engine owned by the firm, detected as "suspicious" up to 32% of these applications..
Most of these "suspicious" applications were those popular with users, such as Twitter or Angry Birds , while other less popular completed the rest of the indicated percentage. This coincides with previous findings from the antivirus firm Lookout , which found popular applications such as Facebook , WhatsApp and Candy Crush distributed in third-party APP stores (which unfortunately were not mentioned either), with adware so powerful that it was not removed even when restoring the settings of device factory . These apps had their normal functionality, so as not to raise suspicions in the user. Of course, in this case we are talking about a Trojan adware (adware "is not universally considered malware", according to Dan Lanir, director of Opswat), but the possibility of downloading an app manipulated in any way from these app stores is there.
As I said at the beginning, it is perfectly possible that you can download an application with a virus or malware from the Internet or from any application store, especially if it is an app store that does not have a reliable reputation. If on Google Play, an antivirus application like Virus Shield -which had a cost of 3.99-, was downloaded thousands of times and even classified among the best apps on Google Play, despite doing absolutely nothing (literally!), It is logical think that similar or more serious things can happen in other application stores such as the Play Store. Therefore, it is not a bad idea to use an antivirus from time to time ( although Google has said otherwise ) either the one that brings your Android or one of third parties such as VirusTotal , MalwareBytes , etc. and use only safe download sources, including app stores like APKmirror.com or F-Droid.org ..
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