Does it work?
Is there any hidden files I don't want in it? Viruses? Trojans? etc.
Is it legal?
Would this fix my ping in games?

Not used it myself so I can't say it is has any trojans etc. I doubt it has and is just simply a util.

No, it's not legal.

This won't "fix" your ping in games. It might make a slight difference but it would only be very slight. Ensuring your connection settings in the game you are on about may improve your ping. So will playing in a server nearer to you. E.g. if you live in the US, play in servers in the US and not those in Europe as your ping will be better.

The weird thing is, I live in Hawaii and I get better ping in canada servers than us servers. So its illegal?