Why is my yahoo email sending spam?

[Les]

People in my address book are receiving spam emails from my account and I am seeing lots of bounced email messages. How do I stop this? I have run my AV & come up with nothing.

[moofu49]

You do not have a virus. Your account has been compromised by a very naughty person.

A computer virus cannot affect an e-mail server. Someone probably phished your password and has accessed your account to spam people in your address book. It is an all-too-common occurrence that results from a weak password. Follow these steps:

1.) Assuming that you can still access your account, CHANGE YOUR PASSWORD IMMEDIATELY. Make it something strong and difficult to crack, as hackers have programs that use a dictionary to crack passwords that are composed of simple words or phrases. Passwords should also include one or two numbers and a special character such as an ampersand or exclamation point.
2.) Notify Yahoo that your account was accessed by an unauthorized party, as they do not take kindly to spammers and you will receive the penalty, not the person(s) who did it.
3.) Never disclose your password to anyone. Loose lips sink ships.
4.) Hackers can also access an account by way of security questions that are used in the event of lost passwords. More times than not, a person will set the security questions to the name of a relative or something distinctive to them, and a hacker can glean this information from a person's Facebook page or any online profile, given that the victim posted it anywhere. If you think this sounds silly, let me tell you that it isn't. Some people will post if and when they are going on vacation, and thieves have used this to stake out homes to break into.

If you want to protect what's yours, you have to be smart.