Friend of mine got this - I imagine a lot of less savvy people might be taken in by this. Firefly's spam filters trapped it

but if this isn't a one-off attack, maybe a general warning should be issued for those who haven't enabled their filters?
Supposedly from "Post Office" <
noreply@fireflyuk.net>
Subject: Returned mail: see transcript for details
Dear user of fireflyuk.net,
Your e-mail account has been used to send a large amount of junk e-mail during the last week.
We suspect that your computer had been infected and now contains a hidden proxy server.
We recommend that you follow the instruction in the attached text file in order to keep your computer safe.
Sincerely yours,
The fireflyuk.net support team.
Content-Transfer-Encoding: base64
Content-Disposition: attachmentHere are the all important giveaway headers (with personal e-mail address replaced by a line of xxxxxxxx)
Received-SPF: soft (Last token {~all} (res=SOFT)) client-ip=85.159.65.150; envelope-from=<
noreply@fireflyuk.net>; x-ip-name=85-159-65-150.cizgibilgisayar.com;
X-Default-Received-SPF: fail (Last token {-all} (res=FAIL)) client-ip=85.159.65.150; envelope-from=<
noreply@fireflyuk.net>; x-ip-name=85-159-65-150.cizgibilgisayar.com;
Received: from fireflyuk.net (unverified [85.159.65.150])
by fireflyinternet.com (Firefly Internet SMTP) with ESMTP id 47000520-1948518
for <xxxxxxxxxxxxxxxxxxxxx>; Sun, 23 Aug 2009 03:06:28 +0100
Return-Path: <
noreply@fireflyuk.net>
X-Verify-Failed: <
noreply@fireflyuk.net> From fireflyuk.net is local but user not authenticated or from g_relay_allow_ip (85.159.65.150)
X-Verify-SMTP: Host 85.159.65.150 sending to us was not listening
From: "Post Office" <
noreply@fireflyuk.net>
To: xxxxxxxxxxxxxxxxxxxx
Subject: Returned mail: see transcript for details
Date: Sun, 23 Aug 2009 05:05:11 +0300
MIME-Version: 1.0
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook Express 6.00.2600.0000
X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2600.0000
X-Originating-IP: 85.159.65.150
Message-ID: <1250993188_18787@email-14089389d>
X-ORBS-Stamp: Your IP (85.159.65.150) was found in the spamhaus database.
http://www.spamhaus.netX-Rcpt-To: <xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
X-SpamDetect: *****************: 17.300001 NakedCR=0.2, SPF Soft=3.0, DodgySource=2.0, SPF Default Fail=2.5, X-Verify-Failed present=2.0, Sender's IP was on Spamhaus RBL=7.0, X-Verify-SMTP present=0.6
X-NakedCr: Body contained naked cr characters
X-Avast: LoadFailed
X-IP-stats: GreyPassed Incoming Last 0, First 8, in=5, out=0, spam=0 ip=85.159.65.150
Content-Transfer-Encoding: 7bit