The federal government has issued a warning about fake airline emails that could contain viruses or spyware.
In recent weeks Qantas, Jetstar and Virgin Australia have all been targeted by scam emails purporting to be from the airlines.
The emails have falsely claimed to be flight itineraries, seat selection fee receipts and flight time changes.
Virgin Australia is the latest airline to post a warning to customers on its Facebook page to beware of the fake emails.
The emails' attachments are likely to contain malware and can be identified by their unusual file extensions, such as ".pdf.zip".
The malware could infect a user's computer and gain access to sensitive data, such as banking details.
The emails are dressed up to look like the real thing, including airlines' corporate colours, imagery and layout.
The government's SCAMwatch website advises anyone who receives the emails and has not booked any travel to immediately delete them. Those who have booked travel with the airline should look for telltale signs that the email is fake, such as unusual email addresses and spelling mistakes.
The emails are also unlikely to contain booking numbers or the customer's name.
SCAMwatch advises computer users to ensure their anti-virus software is up to date.
Gerry Tucker, from internet security company Websense said airline customers are a prime target for scammers.
"One reason they're going after airlines is because air users are very used to receiving their e-tickets from airlines via confirmation emails," he said.
"The bad guys know this, so they're trying to target people who may not notice something's wrong with the email."
Tucker said these types of email scams, known as phishing attacks, are becoming increasingly sophisticated.
"If you look at the attack on Virgin, it's almost identical to what you would get as a traveller... It's also targeted at people who are frequent travellers, maybe from data that they've acquired somewhere else," he said.