This happened to me the other day. Report it to Apple as fraud. It's a way to destroy your app by killing engagement etc. Here you can see the effect it had on my app.

Did your retention take a hit?

This is a scam IMHO. A rival will buy installs of your app for a chosen keyword to destroy your benchmarks. In turn this will affect your ranking in the store and future success. My app appears to be ruined by these practices. It used to be #1 for it's keyword in most countries, and now it can't even rise above a 3 star app (see pic). My retention dropped from around 30% to 1/2 a %, because the downloads aren't real.

This is a technique used by malicious developers to kill your app. The installs kill your apps' retention values etc and make it rank lower for the keyword used to get the install. I do not know this for fact as there is no way to prove it, but my chess app has been ruined by such spikes eg 2 days ago 11000 downloads from Vietnam when I usually get a few hundred. Apple do seem really interested in investigating. Hopoefully they will remove the bogus units from my stats

Thank you.

I'm trying the "Contact Us" inside Appstoreconnect first with the category of fraud. I haven't had much luck discussing issues in the past tho' - I usually get a reply telling me to do the stuff that I have already said to them that I have done.

There are only two apps in my screenshot. Further up there are quite a few ads.

Did anyone find out how to do this?