“SCAMwatch is warning travellers to watch out for scam emails with fake flight itineraries attached – these attachments may harbour malicious software.”
In general, be suspicious of any email that you didn’t expect to receive. For instance, if you weren’t planning any travel, receiving something like this is suspicious.
More info on Scamwatch’s site: http://www.scamwatch.gov.au/content/index.phtml/tag/OnlineScams