When anti-spam tools attack!

412 Precondition Failed error message
The error message I kept seeing whenever I’d try to access my blog.

Despite all my protests to the contrary, it would appear that I’m a spammer. How do I know? Well, the Bad Behaviour anti-spam plugin for WordPress (the software that powers my blog) told me so this evening.

No matter what browser I used (Firefox, Opera, IE) I would still get the same error message, a “412 Precondition Failed”.

I began to panic. The blurb beneath the error title told me that

To resolve this problem, please try the following steps:

  • Ensure that your computer is free of viruses, Trojan horses, spyware or any other sort of malicious software…

So I cracked open a copy of Ad-Aware SE Personal, and when that refused to update I really began to worry. (That’s often a ploy of malware like viruses and spyware, to make sure you can’t update your anti-virus or -spyware software to get rid of it.)

Plan B: Spybot: Search & Destroy which updated and ran fine. Found some cookies that Ad-Aware SE had missed, too. But no joy, I still couldn’t connect to my blog.

I then got thinking, and checked a couple of other WordPress-enabled sites on my server. Odd, I could connect to them. So why not my blog? And then it dawned on me. Perhaps I was being blocked, for some reason, by the Bad Behaviour anti-spam plugin. I fired up my FTP client (WS_FTP Professional 2006) and renamed the bad-behaviour folder and lo-and-behold! that fixed it.

I checked out the Bad Behaviour documentation, and look:

In extremely rare circumstances, Bad Behavior may block actual human visitors. Bad Behavior was designed to target robots, not people. If this happens, the profile presented by your browser matched that seen from actual malicious robots. In most cases, this is caused by over-aggressive personal firewall/browser privacy software. In some cases, this is caused by improperly configured Web proxy server software.

It’s all a bit of a mystery, to be honest. (Maybe this post will help explain it.) But at least

  1. I can now access my blog, having added my own IP address to the Bad Behaviour whitelist, and
  2. I know that Bad Behaviour does its job.

I’m quite relieved I’m not a spammer, after all. Imagine all the self-hatred I’d have to put up with, not to mention the boxes of viagra and Texas Hold ‘Em Poker (can you buy poker in boxes?) that I’d have to store at Potting Shed HQ!

Update: 00:05
I’ve done some investigating, from the bad behaviour logs in my MySQL database and it appears that the problems first began with “Required header ‘Accept’ missing” HTTP error 403 at 18:25:42 this evening from a browser that identified itself as “Mozilla/4.0 (compatible; Synapse)” which according to this list is a bot.

Now, this evening at about that time I was writing a review of Evrsoft’s First Page 2006, but as far as I can recall I didn’t try to connect to my blog through it. I can’t think of anything else that I used that it might be.

Published by

Gareth Saunders

I’m Gareth J M Saunders, 46 years old, 6′ 4″, father of 3 boys (including twins). Latterly, web architect and agile project manager at the University of St Andrews and warden at Agnes Blackadder Hall. Currently on sabbatical. I am a priest in the Scottish Episcopal Church, and I sing with the NYCGB alumni choir.

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