PETALING JAYA, Kuala Lumpur - Devices costing as low as RM47 (S$18) can hijack your home and office WiFi and broadband connection from as far as 1km away.
Worse, they also enable hackers to steal your personal data, including passwords for online transactions.
The Star found that the "WiFi hackers", also known as "WiFi adapters", were sold openly at gadget stores, supermarkets and digital malls as well as online.
An information technology specialist, who wanted to be known only as Thomas, said that a powerful device could hack WiFi connections as far as 1km away from the source.
"When the device is installed into a personal lap top or computer, its antenna would detect WiFi signals.
"It would then tap into nearby networks by hacking their passwords," he said.
Thomas, whose personal network had been tapped, said the "man-in-the-street WiFi pirate" would normally use the tapped WiFi connection to download stuff from the Internet like videos and movies.
Din, another IT expert, said the more sinister hackers would even steal personal data.
"There is a method called man-in-the-middle attack. This allows the hacker to 'sniff' even sites secured with https such as banking portals, e-mail and social media (Facebook, Twitter).
"What this means is that the safety net of encrypted data is no longer in place," he added.
Din revealed a far worse case scenario of a WiFi connection being hacked.
"If the hacker uses the connection from your broadband or WiFi account to hack a government or any website, the trail will lead back to you.
"You may then find yourself in trouble for an act that you neither committed nor had any knowledge of," he said.