Returned mail: Data format error

[3cstephan@cc.wwu.edu]

Dear user of ths.kth.se,

We have received reports that your e-mail account has been used to send a large amount of junk email during this week.
Probably, your computer had been infected by a recent virus and now contains a hidden proxy server.

We recommend you to follow the instructions in the attached file in order to keep your computer safe.

Best wishes,
The ths.kth.se team.

attachment.zip