Avast discovered yet another Android adware scheme involving apps with over 15 million downloads on the Play Store.
Alphabet's subsidiary already removed 30 of the 47 apps Avast found to be carrying the known "HiddenAds" trojan.
Avast used its own Apklab.io tool to spot the large-scale adware scheme, the company said.
Like any adware, HiddenAds makes money by redirecting users to advertising served by some marketing affiliate platform.
Which is why Android adware thrives on the Play Store, and has been since the dawn of the smartphone era.