Hotfix update 0.51 got flagged as malicious when installed on android 🥀
I'm looking at this right now, I'm pretty sure this is a false positive being triggered by Unity's Analytics service. I'm going to look at disabling this in future builds since it looks like this may the cause of some false positives.
There may be a few other potential causes (like apparently a custom icon in Unity can cause this in some instances), either way, I'll see what the root of this issue is for some users.