I have a couple of urls that have become quite attractive to spammers as of late, for some stupid reason. Stupid in that most situations involving spam are stupid, as the inefficiencies would make anyone of any intelligence balk at the very concept. But still, many desperate and immoral thugs persist.

My urls that appear to make spambots salivate with misguided hope are those that allow anonymous users to add content that will be later displayed to others. Specifically, there are two:

• anonymous trac ticket creation
• wordpress comments

Both trac and WordPress have fantastic tools that fight spam (Akismet, for one, is priceless). These tools prevent tons of spam on my sites every day. But thanks to mindless bots, the spam, while pretty much always unsuccessful in creating tickets due to Akismet and captcha, can morph into the DOS category. I was getting 5 apache requests every second, 24×7.

I started using mod_evasive to stop the flood, which certainly helped. But it did not break the spambots to the point where they gave up. I was dealing with some seriously inept and overzealous spambotting – I don’t even have heavily trafficked sites. What recourse is left if you just. keep. getting. mindlessly. hammmered!?

I got out the big gun and decided that, in the case of my trac ticket site, it was better to just move the whole damned url. The ticket site is a part of a larger site devoted to my music player project, and valid users should really navigate through the top site anyway. It took me a while to decide this was best. It’s certainly not optimal for supporting a site that might be heavily bookmarked by end users. It’s kind of out of the box thinking. But in my case it was worth the cost.

For trac, it was just a matter of a couple trac.ini and apache config changes, and then changing the referring websites.

trac.ini:

[trac]
base_url = https://mysite.com/mynewurl

apache conf:

WSGIScriptAlias /mynewurl /var/lib/trac/apache/trac.wsgi

I get spammers slamming my little web sites all the time. A couple of my pages seem to have gotten added to some bot list, and there is no end of attempts to add comments to my WordPress blogs and tickets to my trac issue tracker. There are lots of ways to fight this, and both WordPress and trac have pretty decent built-in tools. One apache-based tool I recently added is mod_evasive, and it is so simple and elegant there’s really no reason not to use it. It’s small and appears to use an in-memory hash table for live state tracking so it shouldn’t slow things down much. All it does is look for rapid access from the same IP address, and put a temporary block on that address for a short time period. So as not to interfere with access by real people, it only takes action against obvious abuse. Here’s my configuration, with notes:

# MDM i thought about changing these to block 5 ticket requests in 60 seconds
# BUT THAT'S TOO MUCH for any other part of my websites
# This really isn't going to solve the trac problem... but i'll leave it for DOS attacks
# I did make it a little tighter:
# lowered page count from 5 to 3 (3 page requests within 1 second)
# upped site count from 100 to 50, interval from 2 to 10 (50 site requests in 10 seconds)
# MDM The only thing getting blocked is me, prolly due to HangTheDJ pings, doh
# Forget this, set it back high again.  It's ONLY going to stop true DDOS attacks.
# We'll set up mod_qos or something else for trac ticket spammers.
# MDM Actually looks like spammers are dropping off...?  didnt see any logging tho... huh
# I'll tighten up a LITTLE; site count from 100 to 30; page interval from 1 to 2; blocking period from 10 to 20
# MDM OK it seems to be working great now!
# But why limit the block to 20 seconds?  I'm upping it to 5 minutes.
DOSHashTableSize 3097
DOSPageCount 5
DOSSiteCount 30
DOSPageInterval 2
DOSSiteInterval 2
DOSBlockingPeriod 300

I’m setting up a private wiki area in my trac wiki. There’s lots of old info regarding trac permissions, easy to get lost. It seems the most current clean way is to use the AuthzPolicy plugin/module, which is available in the base install. There are some steps to go through to get set up, but it’s pretty straightforward.

Go to the admin plugins page, click Trac arrow to open it, find AuthzPolicy, click arrow to open it for instructions. More instructions are here but may not be as up-to-date. When you’re ready, click the enable checkbox and save changes, then configure it. Here’s what I did:

easy_install configobj
emacs conf/trac.ini
  [trac]
  permission_policies = AuthzPolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy
  [authz_policy]
  authz_file = conf/authzpolicy.conf
emacs conf/authzpolicy.conf
  [groups]
  devs = joe, jane
  [wiki:DevPage@*]
  @devs = WIKI_VIEW, WIKI_CREATE, WIKI_MODIFY
  * =
/etc/init.d/apache2 restart

The base Trac is pretty useless for managing users, so let’s get the plugin that fixes that (yes trac is still pretty much a hack 🙂 )…

easy_install TracAccountManager

Now let’s configure it. Same as before, pop it open in the trac admin page. More instructions are here.