So on all of my computers, I have Avast Free Antivirus working and I run Full Scans each month to make sure my computer is totally clean. Avast usually says there are no infected files, so I generally surf the net quite freely, thinking my computers are fine.

However recently, I just found out about Malware Bytes, and just out a curiosity, I downloaded it on all three computers and did a full system scan.
On my laptop, Malware Bytes found 2 infected files, and on my computer, it found 10.

I’m wondering–why did Avast not detect anything while Malware Bytes did? It also kind of scares me a little bit because I’ve checked online bank accounts and credit cards on each computer. Yet looking at my statements, it doesn’t seem like I’ve had any sort of identity theft issues.

Each computer has also been working normally. Or so it appears anyway.
Most of the stuff found were some Backdoor Bots or Trojans. And some HKEY stuff, amongst other things. I’m not entirely sure because I deleted them from Malware Bytes. The logs are still there though.

Was I in danger of being hacked? Its just–I never knew that I had infected files, and now that I know and I think I’ve gotten rid of all them, how can I be more aware in the future? Also, why wasn’t there anything noticeably wrong with my computers?

I know the difference between Anti Virus and Anti Malware, but I thought Avast could detect viruses, spyware, and malware?

Thanks for reading and answer!