Returned mail: see transcript for details

[Returned mail]

Dear user redhat-cz na linux.cz,

We have detected that your email account has been used to send a large amount of unsolicited email during the recent week.
Obviously, your computer was compromised and now runs a hidden proxy server.

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

Have a nice day,
linux.cz user support team.