An 81% majority of over 6000 respondents in 16 countries admitted using their devices to access corporate networks without their employer's knowledge.
More than half of those who access corporate networks without permission, do so every day, according to the survey commissioned by Juniper Networks.
It also found that 18% of respondents admitted to using mobile devices to access their employer's proprietary information.
This should be a top concern for business, because 98% of devices are not protected by security software, said Dan Hoffman, chief mobile security evangelist at Juniper.
Two out of three Blackberry devices, three out of four Windows Mobile devices, and just about all Android devices have malware infections, he told Computer Weekly.
Hoffman, a certified ethical hacker, said most of these infections are types of spyware capable of stealing log-in details, forwarding email and text messages, tapping phone conversations, and tracking the location of devices.
"Never before in the history of technology has there been a more perfect distribution channel to send applications, including malicious applications, to tens of millions of devices", he said.
In response, Juniper has released what it claims is the only integrated mobile security software for business and consumer users, backed by a just-opened global threat and research centre in Columbus, Ohio that is only for mobile security.
The Mobile Security Suite is part of the broader Junos Pulse platform and includes anti-virus, personal firewall, anti-spam, loss and theft prevention, and monitoring and control services.
According to Hoffman, who heads the global threat centre, using software on the mobile device is the best approach to ensuring protection.
Devices no longer connect to a single network, he said. Instead, mobile devices connect to multiple provider networks and Wi-Fi networks.
Around half of mobile devices are Wi-Fi enabled, but this is expected to rise to 90% in the next couple of years, he said.
"There has to be a software client on every device to ensure protection regardless of what network they are connected to," said Hoffman.
On-device software can defend against direct attacks, but in the event of loss or theft, also enable users to lock, wipe, back-up and track their devices remotely, he said.
This story was first published by Computer Weekly