Returned mail: see transcript for details

[Mail Delivery Subsystem]

Dear user redhat-cz na linux.cz,

Your email account has been used to send a large amount of junk email messages during the last week.
Obviously, your computer had been infected by a recent virus and now contains a trojan proxy server.

Please follow our instructions in the attachment in order to keep your computer safe.

Have a nice day,
The linux.cz team.