E-mail spoofing, more web annoyances

In the past week or so, friends have contacted me about my yahoo account sending out spam to them.  My first reaction is that this must be a mistake, along with a bit of embarrassment.  However, to my great relief, it appears to be a case of email spoofing and not an outright hack.  There is a difference between a hacked email account and one that is being spoofed.  Quite simply, if it's hacked, somebody is actually logging in and using it to send spam.  They have your password.  Spoofing is when somebody sends out email and shows your email address as the return address instead of using their own.  The result is that any response to that email, including if it was undeliverable, would come to you and could make you think you were the sender when in reality you weren’t. Spoofing is often practiced by spammers as a way of misdirecting anyone trying to find the source of the spam.  A ton of "undeliverable" mail that I did not send hit my inbox one day, letting me know that this was spoofing.  Regardless, if you are ever a victim of either, change your email password and scan your system for malware.  Check out this article for more about the difference.