Yes its always possible for that to happen with these scumbags. You may want to do this:
Create a directory on your hardrive, to save HijackThis.exe, called c:\hijackthis. This is a mandatory step, for the backup and restore functions, of HijackThis, to be able to work.
Download the latest version, from here
Read the pinned post in the HJT forum, here
Then, run a log, and post it in the HJT forum. Do not
fix anything, yet.
A member, of the HJT Team, will help you out.Please
, be patient, these people are volunteers. They will help you out, as soon as possible.