Security vendor GFI Software is warning London commuters to be on their guard while using the public Wi-Fi services offered by Tube stations across the capital.
Free Wi-Fi services were rolled out across London Underground stations in the run up to last year's Olympics by broadband provider Virgin Media.
Since the start of 2013, the firm has scaled back the availability of its free services, meaning people that are not Virgin Media, EE or Vodafone customers have to pay to access them.
Your wireless data could be intercepted by anyone that may have inexpensive packet sniffing' software installed.
Users of 50 London Overground stations also have the option to connect to the public Wi-Fi services offered by The Cloud.
However, GFI Software claims using these services could compromise the security of commuters' devices and their data, and expose them to attacks by opportunistic hackers.
Phil Bousfield, general manager of IT operations at GFI Software, said the Tube network's Wi-Fi services have no encryption in place, meaning data can be intercepted with ease.
"Your wireless data could be intercepted by anyone that may have inexpensive packet sniffing' software installed," he warned.
"Wi-Fi on the Tube is potentially good for productivity, [but] its use should not be encouraged at the expense of information and personal security," said Bousfield.
He also claimed tablet and smartphone users often have a "false sense of security", as they often do not realise their devices are subject to the same threats as laptop users.
"Malware writers are increasingly turning their attention to mobile platforms, with all devices increasingly at risk of physical or wireless data theft," he added.
