Of course, foxes are certainly not "evil". I think they're very beautiful creatures and I hope to catch a glimpse of one in real-life rather than having to watch Springwatch.
I've never really gotten into the whole Warrior Cat thing; I've never read the books or joined a roleplay. I suppose if in that particular fandom foxes are considered evil then, fine. People roleplaying as a warrior cat will treat you as evil, and I'm alright with that, knowing that they're staying true to the fandom.
However, outside of the Warrior Cat fandom, it would be a different story. It's very rare that a fox would attempt to harm a cat in anyway. In Scotland, red foxes and wildcats are competitors for resources such as food, but it's unlikely they'll try to harm one another. Heck, I've seen videos on YouTube of a cat and fox playing together!
I don't know who heard about this, but during February this year in Britain, there was a news story about a fox sneaking into a person's house, attacking their baby and ended up biting its finger off. This provoked a lot of discussion, and some people were even considering bringing back fox hunting in certain areas.
Now, a fox might prowl around someone's house at night rumaging through their waste bins, but it is extremely rare for a fox to attack a human. This was obviously one of those rare occasions. There haven't been any stories like that in recent years as far as I'm aware. To be honest, I think it's the person's fault for attracting the fox by leaving waste out making it easy for the fox to get it...
Anyway, that's my contribution XD