10 November 2009

The tax office has issued a warning about 'the most sophisticated and prolific' scam it has ever encountered. Last week, HMRC reported over 80,000 instances of a tax fraud email.

A dangerous US fraud email related to self-assessment tax returns is likely to have spread to the UK, a tech expert has suggested.

Webroot threat analyst Andrew Brandt wrote on his blog that con artists have been posing as the Internal Revenue Service (IRS) to infect their victims' computers with malware.

Commonly, these messages are structured by warning the recipient that they have been underpaying their taxes. When the victim clicks on a link, their computer is infected by viruses - allowing the fraudster to steal personal data.

Mr Brandt forecast that, with the paper deadline for self-assessment tax returns in the UK of January 31st approaching, instances of this kind of email would increase.

The only difference likely between the UK and US emails is that the fraudsters will pose as HM Revenue & Customs (HMRC), rather than the IRS.

"We classify the files as Trojan-Backdoor-Progdav (other vendors call this spy Zbot), a general-purpose smash-and-grab Trojan designed to give the malware's distributor total control over the infected machine, mainly for the purpose of aiding identity theft," Mr Brandt added.

HMRC says thousands of people have received emails asking them to supply their financial details electronically in order to claim tax rebates.

Victims run the risk of having their accounts emptied, as well as their personal details sold on to other organised gangs.

Lesley Strathie, chief executive of HMRC, says, 'This is the most sophisticated and prolific scam that we have encountered. We only ever contact customers who are due a refund in writing by post. I would strongly encourage anyone receiving such an email to send it to us for investigation.'

HMRC is also warning people of a growing number of telephone scams with fraudsters posing as tax officials arranging rebate payments. The deadline for tax returns is 31 January, with anyone filing a late return liable to a fine of £100.

Do not open suspicious emails

Tax officials are advising anyone who has received a fraudulent email to contact the fraud helpline on forward it unopened to this address.

HMRC do not send notifications of a tax rebate over email, or request that you update your security certification.

If you receive an email that doesn’t address you by your first name and surname and then asks you to click on a link and/or disclose your details, you may well be revealing your details to a fraudulent website.

If you have received an email from HMRC that you consider to be fraudulent, please forward it to This e-mail address is being protected from spambots. You need JavaScript enabled to view it . HMRC cannot reply to every email, but action is taken on each report received.