Your friends don’t like getting spam, and they certainly don’t like getting it from you.
The good news is that you’re not really sending it. Your computer probably isn’t sending it, either. Someone in your circle of friends may be unknowingly spamming others via your address and their infected computer. Or someone you don’t know could have hijacked your e-mail account.
Before you do anything else, change your email password. You can do this after logging onto your email service’s web site. I can’t give you exact instructions since I don’t know what service you use, but the option is usually easy to find.
And use a strong password.
If you can’t change the password, or if you can’t even log on, your account has been hijacked. Someone has gotten hold of your password, changed it, and is spamming from your account.
This happens quite a bit. Not too long ago, I received a desperate e-mail from a friend who had apparently been mugged in London and needed money quick. It was obviously a fraud. The friend wasn’t in London, and didn’t write like a non-native English speaker. Turned out he had fallen for a phishing scheme and sent his password to someone he thought was Hotmail.
If you find yourself in my friend’s predicament, contact your e-mail service provider to find out what you can do about getting the account back. Follow these links for the larger providers: Gmail, Yahoo, Hotmail.
On the other hand, if you can successfully logon and change your password, your account may not have been hijacked. And if it was, you’ve already taken it back.
So what else could be the problem? I doubt that malware on your own computer is spamming your friends. After all, the only real connection between your PC and your email address is that you usually use one to access the other. But you should run some tests just to make sure. See Remove a Virus or Other Malicious Infection.
A far more likely scenario: Someone you know has an infected PC, and that they are unintentionally spamming their friends and associates. Spammers often use an infected PC to mass-mail junk to every address found on the computer’s hard drive. And they’ll use some of those addresses as spoofed (translation: faked) From addresses.
So if friends are complaining that they’re getting spam from you, let them know that they may be getting it from another, mutual friend. Eventually, one of them will check their own machine and discover an infection.
This particular scenario, however, is unlikely if you know the people getting spammed, but they don’t all know each other.
via – PCWORLD