Some of the characteristics that make email attachments convenient and popular are also the ones that make them a common tool for attackers:
Email is easily circulated – Forwarding email is so simple that viruses can quickly infect many machines. Most viruses don't even require users to forward the email—they scan a users' computer for email addresses and automatically send the infected message to all of the addresses they find. Attackers take advantage of the reality that most users will automatically trust and open any message that comes from someone they know.
Email programs try to address all users' needs – Almost any type of file can be attached to an email message, so attackers have more freedom with the types of viruses they can send.
Email programs offer many "user-friendly" features – Some email programs have the option to automatically download email attachments, which immediately exposes your computer to any viruses within...
Chain letters are familiar to anyone with an email account, whether they are sent by strangers or well-intentioned friends or family members. Try to verify the information before following any instructions or passing the message along.
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 co...