IT contractors should remind companies of the importance of using unique passwords to access their data, according to a network security company.

Many workers use the same passwords at work as they do on their email accounts or social networking sites such as Facebook or Twitter, according to CryptoCard.

This means that obtaining the access password for company information stored in a virtualised network can be obtained simply by hacking a social networking account.

Most companies are unaware what the appropriate levels of control are for cloud computing, when this should be their number one concern, said Jason Hart, vice president of Crypto Card.

Only 27 per cent of companies using virtualised data storage networks have the correct security procedures in place, according to the latest research from Symantec and the Poneman Institute.

"Even if companies have the most robust security software and controls in place, the outdated system of a traditional username and password is simply leaving the business exposed to hackers," he said.