Contractors must be extra careful with their digital information after warnings about 'pocket-based' techniques of theft.

Alexei Lesnykh, business development manager for DeviceLock, said that the removal of corporate hard copy files from corporations is "the most dangerous data leak method".

"In these times of current global economic downturn, simple 'pocket-based' techniques of taking away valuable corporate data have become much more popular and dangerous," he added.

In related news, a joint survey by Symantec and the Ponemon Institute has revealed that 59 per cent of employees who lost or quite a job in 2008 admitted they had stolen confidential company information such as customer contact lists.

Meanwhile, Amit Klein, chief technology officer at Trusteer, said that Zeus attacks have the ability to intercept and modify any incoming or outgoing data or web pages from the infected computer, meaning contractors must take steps to protect their equipment from the attacks.