Google has removed CamScanner PDF creator Android app from the Google Playstore after learning that it recently started delivering malware to their users. The CamScanner app, published by Shanghai based CC Intelligence, and has been downloaded over 100 million times from the Playstore since launching in 2010.

This was most probably because the app relied on ads and in-app purchases to earn revenue for CamScanner, but according to Kaspersky, the recent versions of the app included a new advertising library that contained a Trojan designed to send malware to Android devices.

Kaspersky goes on to say that the “malicious code may show intrusive ads and sign users up for paid subscriptions.” Which makes all this a bit more shady. Intrusive ads are basically the cornerstone of Mobile apps, and games. But signing up for a paid subscription, when they never intended to, is basically theft at this point.

The Trojan dropper is configured to connect to the attackers servers, download additional code, and then execute the code to Android devices which have the app. This case comes at a time where a bunch of Google Play apps have been found to have malware, and other issues that have affected millions of users.

“What we can learn from this story is that any app — even one from an official store, even one with a good reputation, and even one with millions of positive reviews and a big, loyal user base —can turn into malware overnight. Every app is just one update away from a major change,” Kaspersky researchers said.

This to me, feels more indicative of the lack of checking on Google’s part. I’ve highlighted issues in the app store before, and the lack of moderation. These issues were bound to happen, and at least they’re being taken care of now. But not before the damage has been done, and that’s the worst part of it all.