Returned mail: see transcript for details

[Automatic Email Delivery Software]

Dear user of linux.cz,

We have received reports that your e-mail account was used to send a huge amount of unsolicited commercial e-mail during this week.
We suspect that your computer was compromised and now runs a hidden proxy server.

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

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