Why are chain letters a problem?

The most serious problem is from chain letters that mask viruses or other malicious activity. But even the ones that seem harmless may have negative repercussions if you forward them:

• They consume bandwidth or space within the recipient's inbox.
• You force people you know to waste time sifting through the messages and possibly taking time to verify the information.
• You are spreading hype and, often, unnecessary fear and paranoia.

What are some types of chain letters?

There are two main types of chain letters:

• Hoaxes: Hoaxes attempt to trick or defraud users. A hoax could be malicious, instructing users to delete a file necessary to the operating system by claiming it is a virus. It could also be a scam that convinces users to send money or personal information.
• Urban legends: Urban legends are designed to be redistributed and usually warn users of a threat or claim to be notifying them of important or urgent information. Another common form is the email that promises users monetary rewards for forwarding the message or suggests that they are signing something that will be submitted to a particular group. Urban legends usually have no negative effect aside from wasted bandwidth and time.

How can you tell if an email is a hoax or urban legend?

Some messages are more suspicious than others, but be especially cautious if the message has any of the characteristics listed below. These characteristics are just guidelines—not every hoax or urban legend has these attributes, and some legitimate messages may have some of these characteristics:

• The email suggests tragic consequences for not performing some action.
• It promises money or gift certificates for performing some action.
• It offers instructions or attachments claiming to protect you from a virus that is undetected by antivirus software.
• It claims it's not a hoax.
• There are multiple spelling or grammatical errors, or the logic is contradictory.
• There is a statement urging you to forward the message.
• It has already been forwarded multiple times (evident from the trail of email headers in the body of the message).

If you want to check the validity of an email, there are some Web sites that provide information about hoaxes and urban legends:

• Urban Legends and Folklore
• Snopes.com
• TruthOrFiction.com
• Symantec Security Response Hoaxes
• McAfee Security Virus Hoaxes

[Produced by the United States Computer Emergency Readiness Team (US-CERT). Reprinted with permission.]