Simply Carpets Threat?

I inadvertently opened an e-mail from a known company here in the UK called Simply Carpets - the e-mail address seemed to be correct.

The email was headed  "Invoice from simply carpets of Keynsham Ltd" with an attached MS word file. Since I have had dealings with them before I opened it and the attached file. The file was gibberish.

The company knew nothing about it, and there were no outstanding invoices on my account. Nothing was picked up on my security software but I am concerned that I have been the victim of a trojan attack that Norton knows nothing about.

Please advise.