Solicitors are being urged to take action against the outbreak of a major computer virus, which is leaving the profession vulnerable to hackers and costing the UK millions of pounds.

An estimated 15,000 computers in the UK may be infected by malicious software known as GameOver Zeus, which is transmitted by clicking on attachments or links in emails.

Once a computer is infected, personal and financial data is encrypted and held hostage by hackers.

However the National Crime Agency and the FBI say they have taken control of the servers behind the malicious software and secured a two-week window for users to update their security software.

Solicitors are among the professional groups being warned by the government to act quickly in protecting their computers against the virus, the Law Society said today.

Timothy Hill, technology policy adviser at the Society said in the longer term ‘this is an opportunity for law firms to review their cyber resilience’.

He said firms should consider joining the Cyber-security Information Sharing Partnership (CiSP), set up by the Cabinet Office with the security service, Government Communications HQ and the National Crime Agency, to help organisations tackle cyber threats.

Hugh Boyes, cyber-security lead at the Information of Engineering and Technology, said: ‘This is a very serious threat compounded by the fact that too many people have limited security protection on their computers.’

Firms can find advice by visiting the government’s GetSafeOnline website, or the Computer Emergency Response Team (CERT-UK) website.