What is spoofing?
Spoofing is a form of deception, both in the real world and online.
Most offline spoofing is supposed to be funny, but on the internet spoofs are usually serious and may have unpleasant consequences.
A spoofed e-mail might carry a virus or a spoofed website could be used to steal your credit card details.
E-mail spoofing
The most common sort of spoofing online now is 'e-mail spoofing', making an e-mail message appear to have come from one place when really it came from another.
It is generally used by spammers, who do not want their real address to appear in the e-mails they send.
Since the messages they send out have web links in them, they do not care if people click 'reply’ and send an e-mail to the wrong place.
It also makes it a lot harder for ISP to track them down and close their accounts.
There are lots of ways to spoof an e-mail address. The simplest is to find a badly-managed mail server, a computer on the net that is used to transfer e-mail around, and use it to send out your e-mails as if they came from it.
Many viruses and worms now use e-mail spoofing too, sending out fake messages that carry dangerous attachments.
Sometimes the only way you know that your e-mail address is being used in this way is when you get an angry message from someone who thinks you have sent them a virus.
Unfortunately there is nothing you can do to stop this happening, as the spoofed e-mail had nothing to do with you.
Web spoofing
'Web spoofing' is also becoming more and more common.
A fraudster creates a copy of the website belonging to an online bank or a well-known shop, and then sends out a spoofed e-mail pretending to be from the company, with a link to the site in the e-mail.
Anyone who clicks on the link goes to the fake site, and if they enter their log-in or account details, or use a credit card to pay for something, the information is stolen and used without their knowledge.
It may even be used to steal someone's identity and open other online accounts in their name.
Although spoofing can be used to carry out criminal activity it is not itself illegal. However most ISPs have terms and conditions which forbid it, and people who spoof e-mails or websites can have their accounts closed.
History
'Spoof' was originally the name of a card game that involved tricking the other players.
It was invented by the English comedian Arthur Roberts, a pantomime star at Drury Lane in London, in the 1880’s.