Spambot Experiment

On August 28, 2011, I started a spambot experiment on my website.
One inaccuracy that I want to clear up before I begin posting the results: About a month or so into the experiment, I changed the difficulty of the the CAPTCHA image from the default (“Medium”) to easy (overlapping letters and numbers). It does not change the fact that the trap, a forum, was still spammed like heck.
One other note is that my DNS provider blocks major spammers automatically, excluding many before a lookup even occurs.

The setup: One SMF forum with no modifications on a directory that was not published elsewhere on the web. (You could not search for this forum). Guest posting was not allowed on this forum (but I might try guest posting out to see the increase). What was required for registration: Standard acceptance to agreement. Username. Email address. Password. “Easy” captcha image. Attachments were not allowed, since I just don’t think I can handle that kind of bandwidth.

As of 12/24/2011, the trap forum contained 49457 Posts in 45471 Topics by 21747 spammers.

Average spammer registrations per day:

182.75

Average spam posts per day:

415.70

Average spam topics per day:

382.20

Average spammers online per day:

26.47

Registration of spammers Male to Female Ratio:

1:0

Growth of spammers:

Forum History (using forum time offset)

Yearly Summary	New Topics	New Posts	New Members	Most Online
2011	45482	49468	21747	81
December 2011	32814	33915	14939	81
November 2011	11989	13695	5079	49
October 2011	620	1798	1534	18
September 2011	55	56	189	7
August 2011	4	4	6	2

One might think that spambots typically just register, spam once or twice, and leave forever, but this seems not to be the case for all. Indeed, many of the spammers returned multiple times. When these statistics were recorded, the user threshold timer was 15 minutes. This means that, per each logon, a minimum of 15 minutes activity was recorded. (I’ll reduce this for the next experiment). The record-holding bots were as follows, I’ve included how many posts were made by the top bots:

racing-games

5h 53m
Surprisingly, No posts were made by this bot.

LEROTOL

3h 23m

Posts: 248 (5.767 per day)

barigatabletokcc

2h 55m

Posts: 85 (2.179 per day)

AntuanetteLak

2h 9m

Posts: 1

ivilus

1h 53m
Posts: 959 (29.969 per day)

CalOvavaIdodo

1h 48m

Krancualeks

1h 48m

onlinebuydrugss

1h 32m

barbosovviagruu

1h 27m

Orancualeks

1h 16m

I will be resetting the experiment. Here are the changes:
First, enabling guest posting and disabling moderation queue for guests. Guest posting of polls has also been enabled.
Account deletion is no longer allowed (I am not sure if any spammers deleted their accounts or not).
Registration verification has been disabled.
User threshold decreased to 1 minute for accurate time keeping of bots.
All currently registered members were deleted to start “anew”.

Those interested in seeing the forum can contact me via. comment, and I can send them a link. I do not want to publicly share it since the links are dangerous and I don’t want people clicking by accident.