You should contact the company that ran the inquiry and ask them about their authorization and what it was for. It could be completely innocent, and an actual inquiry, but it could also be an indicator that someone is checking your credit for something else.
As far as the credit reporting company goes, they got a real inquiry, whether it was fraudulent or not is up to you to find out and report. If you find that it was a fraudulent report, you can put a "lock" on your credit report with all agencies to prevent it.
It could also have been something as simple as a mixed up SS#.