the boss checked my computer history and saw AF

[Aractus]

No, it doesn't block "whatever you want it to". It blocks requests to sites that match specific patterns. It can't block actual malware. If a new site popped up with malware on it, uBlock is useless. That doesn't mean it's not a great tool; it is, but people who overstate what it actually does are contributing to a greater problem, which is people thinking they are more secure than they are!

There are lists dedicated to blocking malware, and it can incorporate the MVPS HOSTS‎ file also. I'm not at all saying it's a complete tool, however it is important because the ransom-ware and other malware are targeted at advertisers. That's not an opinion, it's a fact - and it's why kickass torrents has been blocked by Google's Safe Browsing at least 3 times now in the past 12 months. Not because its server served malware, but because malware was on the website served through its advertisers. However, if you had uBlock running when visiting the website you were never in any danger in the first place. There has even been malware found embedded in Youtube ads.

Y'know, I've heard this one multiple times over the years, and it still astounds me that people bring it up.

It's just wrong on so many levels.

Ignoring the fact that most of the Internet runs on Linux, Windows by default enables services which have dangerous flaws in them. It also stores passwords insecurely, doesn't do separation of privileges properly, etc.

You can sit in a Windows network and compromise it usually without using any malware, by exploiting these weaknesses.

That's a different matter to security vulnerabilities through malware. Windows is the most targeted OS. But that's not the core weakness - the core weakness is usually Java (which is being mothballed) or Flash or a browser vulnerability or a combination thereof. Weaknesses in the Operating System wouldn't matter if web browsers were hardened in the first place. So my point again is that meaningful security enhancements can be made just by installing uBlock, either not running Flash or setting it to "ask every time", and of course not using the Java plugin.