Remote workers are becoming less vigilant in their online behaviour, according to Cisco's annual study on security awareness and online behaviour.

The survey of 2,000 remote workers in 10 countries found that the majority feel more vulnerable outside the office, but that perceptions of security seem to be softening.

The number of people working at least one day a week from home is expected to reach 46.6 million by the end of 2011, according to figures from Gartner.

More than half of the IT managers surveyed believe that remote employees are less diligent about security than they were a year ago.

Cisco believes that this shift in perception may be down to the switch from overt to covert attacks.

Although today's threats are more dangerous because they threaten personal identities and corporate data, their invisiblity can result in a loss of discipline, particularly with remote workers.

"While working at home, people tend to let their guard down more than they do at the office, so adhering to security policies does not always seem applicable or as necessary," said John Stewart, chief security officer at Cisco.

"The blurring of the lines between work and home, and between business lives and personal lives, presents a growing challenge for businesses seeking to capitalise on the productivity benefits of the remote workforce."

The survey suggests that remote workers are more likely to open emails and attachments from unknown or suspicious sources, and to use work computers and devices for personal use.

They are also more likely to hijack wireless internet connections from neighbours, and access work files with non-protected devices.

The findings have prompted Cisco security executives to offer recommendations to IT professionals on how to protect against threats without losing the business benefits of distributed and mobile workforces.