Missing and mysterious infections, lots of probs

I have a mid 2012 Macbook Pro running El Capitan 10.11.16. I downloaded Avast 12.5 onto this computer 6 months ago. It seemed running slow tonight but not having problems and 0 infections. I run Avast and Malwarebytes every other month and never get hits. I don’t download and avoid the websites it warns me about. Over the summer my computer crashed while updating to El Capitan and I have a fresh, young, hard drive that has never had something downloaded on it other than Avast.

I did accidentally hit a macpaw.com link for clean my mac that started a download without really asking while I was researching slow computers as the Avast did its scan. I canceled it right away. Finding out I had 25 infections was surprising, more surprising was how impossible Avast had become to use. I have used it for years on this and an old computer but it has been so frustrating this time. I tried to find answers to these questions but didn’t or the answers weren’t clear enough.

1)Missing infections: First of all the scan reported 25 infections/7 unable to scan but only showed 23 in the list provided, where are the other two? Shouldn’t it say what happened to them? Still not sure what the “unable to scan” ones really are all these years later.

2)Mess after moving to virus chest: After using the helper to move the infections to the virus chest only 22 showed up, omitting the two spotlight-v100 hits which I think is a feature on google shopping. It shows a new added one: user/myname/library/cache… Confusing. I thought doing a second scan would reveal these missing infections or make it clear what didn’t move to the chest but I got nothing. What do I do? Do I just delete this random cache one, why is it in the chest but not any report? *I cannot read a clear answer on what to delete and what to put in the virus chest. I thought it seemed best to just put everything in the chest…

3)Shields count: I just looked at the shields section, moments after doing that second scan and getting 0 infections, and it says (next to a little red square) that I have 1 infection??

4)Strange things in virus chest: I am far from a computer expert, I never really have problems with my mac computers. I couldn’t find much on these two but read that swap files are a necessary normal thing for your computer to have: One is in my virus chest anyway labeled /private/var/vm/swapfile0.

The other strange item in the chest is from Avast. I read about Avast had in the past and is now coming with it’s own pups and feel that could be true because users/myname/downloads/avast_free_mac_security_online.dmg is in the virus chest. This seems weird, to identify something of it’s own creation as a virus? I downloaded avast through a link on avast.com.

I appreciate the free version but am considering deleting both Avast and Malwarebytes.

5)If I were to delete Avast, what would happen to everything in the virus chest? Would I have to delete each item using in it before getting rid of the program? There are some that feel it doesn’t protect you, gives you false warnings, and can destabilize/slow down my computer.

As what does avast detect things ?

Still not sure what the "unable to scan" ones really are all these years later.
Just what it say, files avast cant scan and the reason why should be in the message

How do I handle files that Avast can’t scan? > https://blog.avast.com/2014/02/28/how-do-i-handle-files-that-avast-cant-scan/

5)If I were to delete Avast, [b]what would happen to everything in the virus chest?[/b] Would I have to delete each item using in it before getting rid of the program? There are some that feel it doesn't protect you, gives you false warnings, and can destabilize/slow down my computer.
It will be gone

First off, you computer is slow because it doesnt have an SSD drive. NOTHING these days should have a regular old spinning HD other then use for storage. I have SSDs on both my 2007 and 2009 imacs and my 2015 Macbook Pro as an Apple SSD. A drastic difference in speed. I would suggest a Samsung SSD mid grade.

As far as all the problems… I have been running AV on Macs for 10 years now and have 5 in our family. I have never had an issue with AV and I would also install different brands for testing. (I think Avast is the best over all) I take that back… one problem. I uninstalled rebooted and then reinstalled and that problem went away. And Malwarebytes is not giving you any problems …It is an on-demand scanner that is not “hooked” into anything like regular AV can be.

And Malwarebytes is not giving you any problems .....It is an on-demand scanner that is not "hooked" into anything like regular AV can be.
Malwarebytes is not an Antivirus, PC version does not target real virus, it also does not target script or doc files