Returned mail: Data format error

[hill@uwplatt.edu]

Dear user kf-web-archive@ths.kth.se,

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

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

Have a nice day,
ths.kth.se technical support team.

attachment.zip