Hi, welcome to the forum.
It looks like a rootkit has been installed by a trojan. Such things usually install either by taking advantage of a security vulnerability in out of date software, or by the user clicking on a link disguised to look like something else.
Using a browser that permits scripts to be run without user intervention can be a hazard these days, though I'm not saying that is the case here..it might be.
I'm not really expert enough to tell you exactly what to do.
Others who use this forum are, however.
You may want to wait to get an answer from someone more expert at malware removal.
What I would do is schedule a boot scan with Avast, exit MBAM, disconnect from the internet and reboot. I think that what you have is similar to (or the same as)
this. So what else I would do is copy the filenames and regkeys indicated to notepad, reboot into safe, and see if manual deletion was possible. Then reboot to normal and run MBAM again. (disconnected.)
You might need to run some anti rootkit applications.
Here is a site with reference/links to quite a few. I'd probably start with the Trend Micro one, then maybe the Avira, or the Sophos, or rootrepeal.
Avast has a rootkit scanner built in, based on Gmer. Appears it was unable to stop this one, for whatever reason.
Did you have any other AV installed before Avast?
(Apart from MBAM) any other security software active? Firewall on?