The programs in question worked normally, but 'defrauded' the mobile ecosystem by showing disruptive ads capable of ruining the experience of users and generating fake ad-clicks in the process.
Here's all you need to know about them.
Apps impairing device functions with disruptive ads
Though Google has not revealed the names of removed apps, the company did say that they all showed disruptive ads to Android users.
These ads, according to the company, appeared in unexpected ways and interfered with the usability of key device functions.
Imagine not being able to make a call or read a message due to a full-screen ad, for instance.
Detection with machine learning techniques
Google says that many of the ad-laced apps appeared innocuous, but its teams were able to detect them using novel technologies, including an innovative new machine learning-based approach.
It helped the team flag when the apps showed disruptive ads, ultimately helping the internet giant remove them from its app store as well as ad monetization platforms, Google AdMob and Google Ad Manager.
Out-of-context ads on the rise
In addition to announcing its action, Google emphasized that out-of-context ads are particularly on the rise in the Android ecosystem.
These ads are those that appear on any screen of a phone, even when the app causing them is not being used.
This not just ruins the experience of the user but also generates fake ad-clicks, wasting the advertiser's money.
Goal to build on these efforts
Now, Google wants to build on this and develop more powerful tools to take on "malicious developers [who] continue to become more savvy in deploying and masking disruptive ads."
"We will continue to invest in technologies to detect and prevent emerging threats, including disruptive ads, and to find more ways to ensure that users and advertisers are protected from bad behavior," the company stated.