The email message below: "A C93 Virus has been detected in your mailbox," is a phishing scam designed to steal Microsoft Hotmail/Live/Outlook user name and password. The email message was not sent by Microsoft, but by cyber-criminals, whose intentions are to trick the recipients into hijacking their accounts, and use it for malicious purposes.
The Fake or Phishing Outlook Email Message
A C93 Virus has been detected in your mailbox, you are required to apply the new Norton AV security anti-virus to scan and to remove all Trojan and viral bugs from your mailbox Account, Failure to apply the scan your mailbox will be De-Activated to avoid our database from being infected.
Click on Optimal Scan and Log in to apply the service.
Do not click on the links in the email message, because they will take you to a fake or phishing Microsoft Outlook website designed to trick you into entering your username and password on it. If your Outlook username and password are entered on the fake Outlook page, it will be sent to the scammers or cyber-criminals behind the malicious email and website.
Once the cyber-criminals have gotten a hold of your username and password, they will hijack your email account and use it for malicious purposes.
Please note that Microsoft and other email providers will not never ask you to apply any form of security scan to remove a virus, Trojan horse or any other malicious programs. They will remove the threat for you without asking.
If you were tricked by the malicious phishing scam, please change your Hotmail/Live/Outlook immediately.
If you are unable to, click here to report it to Microsoft.
This scam is similar to the following: