I think I read the book the movie was based off of years ago. I also think back then in the 80s there was another version of this movie out from the 1970s.
Basically weird scarab trapped in a metal case that looks like a bug body. Drinks the blood of someone it attaches too. It then makes them younger. There is a little girl that I think is helping her grandpa in this. There are people he gets in a fight with over the scarab that wanted it for their own purposes.