No. Contiguous files are not malicious. They refer to a whole file in one spot on your hard drive. When you access data on your hard dive, the computer just tosses the file back anywhere that it can. This can make it very hard for the computer to find the files again on the hard drive. This is what defregmentation on you computer is for. It takes all these files thrown all over the place, and sorts them to be place all the pieces back together. This makes them contiguous files.