Helium pro – several questions

[Android Central Question]

I loaned a friend my back up android phone for a few days and it came back with malware which would pop up new browser windows on every browser I opened with 'Ads'. I followed all the usual recommendations to eliminate the malware but failed.

So I started thinking that it was a big mistake that I hadn't backed up using helium . So I went from the standard version to the pro version, and successfully backed up my primary and secondary phones.

My questions are these: it appears to me that if helium doesn't back up system files then helium is useless as a antidote to malware . Is this correct?

Question 2 I also can't find on my PC where the PC version is stored .

Question 3: on Google Drive I can see the uploaded backups I have there for both phones . They look identical to the ones that Google makes for itself routinely. Are they?

Will the backups I made be overwritten next time my phones back themselves up using the android native utility? If so what is the point of a utility like helium?

My phones are a OnePlus 3T running android/oxygen 8 and Moto G running android 7.

Thank you for taking the time to read my post