Thank you for your config. your 8.1 system's similar to my own,
and I'm considering trying your Chrome browser. My opinion, gleaned from Wise Ones here on MT, is the built in User Activated Control (& the Windows Defender & Firewall) offer enough protection, THAT and using (as illumination mentioned) "
...the ole head as well"!
On (2) other systems, we've used 1) Malwarebytes free on a windows 7 system, & 2) HitmanPro free on an older XP, both with good results (in particular the HitmanPro). Be sure to back up your files first. In addition to the Chrome extensions recommended, Ghostery smoothly blocks advertising, analytics, beacons, privacy, & widget trackers, & it's also available on Chrome. Sandboxie is a remarkable containment protection. Version 4.06 is on 2 of the older home computers, & I await (patiently, I think..
) their beta version 4.07.05 (with fixed functionality for Win 8.1) to graduate as their next version. What kind of malware problem did you have before?