Security experts today warned that the impending total ban on smoking in UK workplaces could be used by social engineering hackers to steal sensitive corporate data.

In a recent exercise undertaken by security consultancy NTA Monitor, a tester was able to gain access to a corporate building through a back door that was left open for smokers.

Once inside, the tester requested to be taken to a meeting room, claiming that the IT department had sent him. Even without a pass, he gained access unchallenged and was able to connect his laptop to the VoIP network via a telephone point.

Roy Hills, technical director at NTA Monitor, said: "It used to be that companies 'left the back door open' in terms of internet security. Now they are literally leaving their buildings open to accommodate smokers.

"We are experiencing a surge in demand for social engineering tests as hackers are turning to social techniques to infiltrate corporate networks."

He added that the exercise proves that once inside a corporate building, an attacker can use social methods on employees to gain access to restricted areas and information.