The study, commissioned by RSA Security, showed the problem is getting worse. Last year researchers found only 15 per cent of wireless networks were unsecured. This year that figure rose to 36 per cent. The picture in New York and San Francisco was equally troubling with 38 per cent of wireless networks unsecured in the former and 35 per cent in the latter.
Phil Cracknell, chief technology officer, netSurity and research author said the results were "another stark warning to unsecured businesses to get their act together."
He added the rapid rise in wireless hotspots ran in parallel to the increased risk to businesses that operate wireless networks with little or no security.
"Accidental or intentional connection to a corporate network can bring with it a series of security issues including loss of confidential data and installation of malicious code," Cracknell warned.
He said mobile users knew where to find wireless networks and how to connect to them. "The question is: whose network they will access and what they will do when they are there?" said Cracknell.
Wireless networks have grown in popularity over the last few years. Arthur Barnes, security consultant for Diagonal Security said part of the problem was with the appearance of "rogue" or unauthorized wireless networks installed by users without the knowledge of their IT department.
"Employees think that they are being clever by buying access points and working around IT departments," said Barnes.
He added that users install access points and "get on with it while the IT
Barnes said organizations needed to have technology in place that could detect and shut off unauthorized access points to protect them from hacking attempts.