pretending to be banks and asking for security details so they can clear out customers' accounts.
The scam is known as "Phishing" because the conmen "fish" for information such as account details and pin numbers by asking a series of questions.
The criminals often pose as high street banking or credit companies - Visa has recently been used to dupe people into giving details.
Victims are sometimes directed to websites that have been set up to look like they are the official site of a well-known bank or credit company.
They are then directed to a part of the site that asks them to provide details of their account and security numbers.
The crime has become a problem in the UK during the last six to nine months.
In the US last year banks paid out more than $1.2 billion after account holders after people fell for the con.
Phishing rates are soaring at an alarming rate and the websites are becoming increasingly common - there is a 50% month-on-month increase in phishing sites.
In October alone, 44 Major brands were hijacked by fraudsters.
Mark Murtagh, an internet security expert, said: "Never click on email links themselves. Never open up attachments being sent to you within emails.
"The warning is clear - beware of fishing expeditions asking you to confirm personal information. The chances are yopu are being scammed."
