For years companies have been warned that the biggest risk to the security of their business is their own staff. Now, the finger is being pointed more precisely at the more junior members of the team.

In independent research conducted on behalf of internet security specialist SurfControl, almost half the HR and IT departments surveyed nominated those in junior positions as most likely to expose a company to the greatest threat.

Students with no interest in the company, and bored receptionists with time on their hands, are significantly more likely to use file-sharing services such as Kazaa, or open anonymous emails with unsolicited attachments, according to SurfControl. The only way around the problem is to educate and inform all staff of the company email and internet policy, and improve network administration.