We just received notification that Trend Micro has raised the Alert for the new MYTOB virus to medium. Trend Micro has an excellent write up at:
The worm appears to be memory resident and spreads by sending a copy of itself as an attachment (account-password.zip) in an email message using its own Simple Mail Transfer Protocol (SMTP) engine. It also installs malware which Trend Micro is calling TROJ_MONURL.D. Trend Micro has removal instructions and more information about the malware at the link above.
Use extreme care when opening your email. Do not open zip files or other attachments that you are not expecting to receive or from suspicios emails.