The Guardian newspaper's jobs website has warned 500,000 users that hackers may have got hold of private information held on the site after a "sophisticated and deliberate" attack.
The paper said not all users were at risk, and it has emailed those who are. The email, sent on Saturday, said data relating to job applications "may have been accessed". It said the incident was now being investigated by the central e-crime unit at New Scotland Yard.
The mail advised people to:
1) Contact your creditors, even if they have not been affected, so that they can monitor your accounts to ensure they remain protected.
2) Contact a credit reference agency: Callcredit, Equifax or Experian provide suggested steps to resolve the situation and prevent it happening again.
3) Contact CIFAS protective registration: If you think you have been a victim of identity theft you should consider subscribing to CIFAS. This places a notice on your credit file indicating that your name and address may be used to perpetrate identity fraud.
It also provided links to various websites for further advice on identity fraud.
The paper said it had been assured by its provider, Madgex, that the site was now secure and that it had contacted, or tried to contact, everyone at risk.
The US version of the site was not affected. The paper declined to give any technical details of the attack until the police investigation was over.
Although no financial information is believed to have been lost, even a standard CV and covering letter can provide a decent start for identity theft.
Hackers have previously gone after recruitment sites like Monster.com to harvest data for ID fraud or for "spear phishing attacks" - personalised email scams. ®