Defender with Malwarebytes as already mentioned should be enough. What false positives do you get exactly?

Personally I have a Linux distro on my PC and don’t need AV software at the moment.

These people are called “tankies”. It’s communists who like militarism and imperialism, as long as it’s of their own flavor. The internet has many such “bunkers” where these people congregate. They unironically support the countries you mention, and they do not represent the entire left-wing community.

I’d argue that they aren’t the result of capitalist policies being shitty. Such communities have existed on the internet since the early 00s. It’s just their ideology.

Why are they on lemmy? My guess is that Reddit banned some of their communities for posting violent content (threats of violence etc.) so they moved to lemmy, which does not censor people to the degree Reddit does.

The .ml for lemmy.ml supposedly stands for “marxism leninism”.