Jetstar has warned customers about scam emails featuring fake itineraries that may contain a computer virus.
The airline said on its Facebook page that some people had reported receiving the fake itineraries and warned customers not to open any attachments on the emails.
The emails have the subject line "Jetstar Flight Itinerary".
One man who had received the email posted on Facebook that the email had "all sorts of things wrong with it", but that it "had the right layout and pictures as per my real itinerary". He said the fact that it had the wrong booking number and wrong email address was a giveaway that it wasn't real.
Another passenger complained that she had been taken in by the email but had been saved by anti-virus software.
"Too bad if you were expecting a genuine email from Jetstar for changes made to an itinerary yesterday, like I did, so of course then when I received the spam this morning I tried to open it," she wrote.
The airline advised passengers that its itineraries are no longer sent as PDF attachments and are now contained in the body of its emails. It said that the only attachments on official Jetstar itinerary emails would be PDFs labelled "Tax Invoice".
"We have reported this to [the Australian Competition and Consumer Commission website] SCAMwatch and will keep you updated as we learn more about this scam," the airline said on Facebook.
A spokesman said that the number of reports to the airline about the scam emails had been steadily decreasing since Friday.
Hoax-slayer.com, which warned that malware in the emails could steal personal information, said other airlines, including American Airlines and Delta Air Lines, had been targeted by the scam in recent months.