Spam mail is sent from my yahoo and hotmail accounts. What might be the reason of this and how can I stop it?

From my hotmail accounts spam mails are being sent to my contacts. I tried changing the password but it continued to happen. I suppose there is something in my computer. What might be causing this and how can I prevent this fom happening.Spam mail is sent from my yahoo and hotmail accounts. What might be the reason of this and how can I stop it?
Your account got compromised. First change your password. Account help.http://help.yahoo.com/l/us/yahoo/acct/in鈥?/a> for just about anything to do with your account. Then run anti Virus and Anti Spyware. Should be fine then.Spam mail is sent from my yahoo and hotmail accounts. What might be the reason of this and how can I stop it?
Sounds like your E-mail account has been compromised, or you picked up a virus.

Immediately have your computer checked for a 'bug' or 'bugs.' If you have the proper programs, do the scans yourself, if not you need to take your computer to some one who can.

Once it is clean of pests, install a firewall and an anti-virus program if you do not have one yet.

I strongly recommend a program for malware and adware also.

After you finish this, then go in and change your password, using a good strong one - yes, in both of your E-mail accounts.

Also, check your account information and make sure no information was changed, if it was change it back immediately.

Then, you will have to inform your contacts that it was not you sending that mail, but they need to check their computers in case they were also infected.