How do I fix search and browsing issues after deleting plists related to 'Megaunitfld' malware on Mac?

Recently, My Mac showed a notification saying “Megaunitfld” will damage your computer. I searched on the web to find how to get rid of the malware, and found an article that told me to enter into my Finder, enter some pathways to LaunchAgents and LaunchDaemons, and to delete suspicious plists that had obscure names. I completed the steps, but afterwards I realized that I wasn’t able to search or browse the web on my computer. I tried using Chrome and Safari, but both apps told me that there was an issue with my proxy server. I then followed the steps to reinstall MacOS version 10.15.7, but the issue persists. What can I do to delete the malware and return to normal usage?

[Re-Titled by Moderator]