4. Email Address Spoofing

Spoofing is when an e-mail message appears to come from a legitimate source but in fact is from an impostor. E-mail spoofing can be used for malicious purposes such as spreading viruses, trawling for sensitive business data and other industrial espionage activities.

If you receive a snail mail letter, you look to the return address in the top left corner as an indicator of where it originated. However, the sender could write any name and address there; you have no assurance that the letter really is from that person and address. E-mail messages contain return addresses, too –but they can likewise be deliberately misleading, or "spoofed". Senders do this for various reasons, including:

  • The e-mail is spam and the sender doesn’t want to be subjected to anti-spam laws
  • The e-mail constitutes a violation of some other law (for example, it is threatening or harassing)
  • The e-mail contains a virus or Trojan and the sender believes you are more likely to open it if it appears to be from someone you know
  • The e-mail requests information that you might be willing to give to the person the sender is pretending to be (for example, a sender might pose as your company’s system administrator and ask for your network password), as part of a "social engineering" attack 
  • The sender is attempting to cause trouble for someone by pretending to be that person (for example, to make it look as though a political rival or personal enemy said something he/she didn’t in an e-mail message) 

Here is an example of a spoofed email made out to look like it originated from administrator@puc.net

email-address spoofing