The last few weeks and months have seen a pretty steady drip of news headlines touting adware-laden apps found to have made their way into the Google Play Store, such as this recent batch of camera and VPN apps that managed to rack up several hundred million downloads. The pattern is essentially a giant game of Whack-a-mole, where the apps sneak in and score a slew of downloads before they’re found out and booted from Google’s app marketplace — at which point the damage may already have been done.

It’s a pattern that keeps repeating itself, with a malware researcher reporting on another batch of apps infected with adware and all sorts of other security issues — 172 such apps, to be specific. Luckily, however, most of them seem to have been removed at this point from the Play Store.

According to researcher Lukas Stefanko, the 172 apps found in a study during September, unfortunately, garnered more than 335 million installs.

Adware, as you can see, was far and away the biggest problem with this latest batch of sketchy apps. Again, though, it’s good news that they appear to be mostly gone from the Play Store — that’s according to Stefanko, who told The Next Web “If not all of these apps, then definitely most of them are not available on Google Play anymore.”

To put this in context, however, Stefanko’s data above only reiterates the problem we mentioned at the outset, about the constant stream of problematic apps stealthily making their way into the Play Store. Based on research from Stefanko, who studies blogs, news reports and lots of other sources including tweets from researchers like him, Google’s app store in July actually unwittingly hosted a greater number of sketchy apps (205) that had racked up 32 million installs. See the problem? From 32 million installs, in other words, to more than 335 million in a span of just two months.