Have you been told by someone you know that they think your e-mail account has been hacked? It seems like you see it more and more today where people get their e-mail accounts hijacked. E-mails are sent to everyone listed in the e-mail account's contact list that contains a link which is malicious. If any of your friends who open the e-mail from your hijacked e-mail account and they click on the link, more than likely their PC has just had some malicious payload installed on their PC. And so the cycle continues. So what do you do if your e-mail account has been hijacked? Here are some steps you can take to gain control back from the cybercriminal.
More than likely you logged into your personal e-mail account on a PC that had some sort of malicious software installed that was able to steal your login credentials for that account. If you only log into your account from your home PC, then your home PC has some sort of malicious software installed and it needs to be cleaned. Make sure you have an anti-virus product installed and that the virus signatures are current, then scan your PC and remove any malicious software that is found. If the scan comes back clean, I recommend downloading free version of Malwarebytes Anti-malware tool from http://malwarebytes.org/. Follow the instructions and remove any malicious software that is found.
Removing the malicious software is just the first step. You need to regain control of your e-mail account by doing the following steps.
1. Change the account password and make it a strong password.
2. Confirm that the "alternate e-mail address" is your other e-mail and not the criminal attacker's so that they won't be notified of the password change and other changes.
3. Change the answers to your security questions.
4. Change any other information that your e-mail account administrator would use to verify the account.
5. If all these efforts fail, open a new account, notify the e-mail administrator and your contacts, and close down the old account.
As always, the best protection from malicious software and other online attacks is to have a firewall and anti-virus software that is kept current. Also patching 3rd party applications like Adobe Reader/Flash, Java, as well as your Windows updates is critical to stay protected. Probably the best tool you have against is your "online behavior". Stay away from peer-to-peer sites where you can download "free" music and software, don't surf porn, and don't randomly click on links without checking into things. Your motto when online should be "trust no one". Combining all these will keep you protected against malicious software.