Hah, if I could find it's pic I wouldn't be asking because I could simply backtrack it. Well, here's the thing - it looks closely to this http://upload.wikimedia.org/wikipedia/commons/thumb/c/c4/German_helmet.svg/550px-German_helmet.svg.png Except it's more blocky and has back neck and ear covers. It's found on lower level Imperial Troopers when playing the Republic missions.