Forum spamming takes several forms, and appears to be on the increase.
This is not the same as "post count spam", the posting of inane, useless comments, strings of emoticons and nothing else, in order to increase post count and rank - behaviour which is frowned on in most forums.
- A "disposable" public webmail, though many forums are responding by blocking public email services, though the potential list is large. The email host may also turn out to be a porn site or a parking page.
- An IP address that may be an open proxy (banning ALL proxies is not possible, as some ISPs force proxying).
- In some cases, the IP address may be a spam-friendly host.
- A bulk spamming campaign is usually made on a large list of forums, while some poorly managed ones show the marks of many spam attacks.
Types of Spam
User info spam
Entering a spam link in the users website info of a created but inactive user can provide a link back to the spammers site, though many forums do not permit guest or search engine browsing of user info. Inappropriate links on an active user are more likely to be spotted in posts.
Inserting one or more links to sites that are inappropriate in a posting signature. A degree of leeway is normally given on signature content, but pure linkspam is generally cause for a ban.
Signature spammers generally make posts that are very similar to post count spam, inane praise and "me too" posts.
First post spam
Often referred to as a "drive by spammer". The post should not last long an any well-run forum, and while the account is banned after the event, they will make a new account next time.
A behaviour noted more and more on forums, where the first poster asks a question, and another forum newbie just fortunately happens to have the perfect (spam) link.
A new tactic, where a seemingly sensible, helpful or innocuous post is made, then later edited to contain spam - the best antidote being limited editing time, also a prevention against some other forms of disruptive behaviour, such as starting an argument and then editing the original post.
Posting a guide, with pictures, to several forums, and actually making a slim attempt to keep to topic, seems to be a behaviour associated with several software products that have excessively generous affiliate schemes. While less objectionable than completely off-topic spamming, it is still an attempt to gain free advertising, rather than a genuinely helpful contribution.
Guest post spam
Most forums do not allow guest posting, for the simple reason that it will be abused.
More so than any other part of a forum, any guest posting areas need to be ruled with a rod of iron, and ideally, subject to some form of IP filtering to prevent anon proxy abuse - people get a lot braver behind an anon proxy, than when it's their own IP that is being logged.
The typical forum spammer may be using a tool such as Xrumer, which the authors go to great lengths to claim is not a spam tool, though it has little purpose other than objectionable scattergun posting to a ridiculous number of forums. The most common CAPTCHA validations are beaten, and a "drive by" spamming attack is made.
The Admin's counterattack
There are several tactics used to deter bulk spammers, who care more about the number of forums they can place their spam on, than catching up with those that act decisively against them.
- New user restrictions, eg. first post moderation, no link posting by probationary users.
- Public / spam-friendly email bans
- Proxy bans
- IP address range bans
- Content filtering
- List exchange
Stop Forum Spam is one resource which collects and collates spammer details, the more forums use it, the more powerful it becomes.