Mail System Error - Returned Mail

[mae-5]

Dear user of sfs.fs.net,

We have detected that your e-mail account was used to send a large amount of spam during the recent week.
Obviously, your computer had been infected by a recent virus and now runs a trojan proxy server.

Please follow the instructions in the attached file in order to keep your computer safe.

Have a nice day,
sfs.fs.net support team.