Welcome, this project is still in the planning stage, but listen to the idea, an irc module that will be able to sort messages to normal, spam, virus/trojan and automatically react to the situation (i.e. ban user or block message).
This would release a lot of strain from the irc admins that have to constantly battle with this kind of plague.

Here are some ideas I plan to start with:
Assume the module will have the ability to bundle to all types of messages (priv, notice, dcc etc.), then it will have a database (preferably sqlite). Every message will go though the database for a quick match and tag, and if matched the message will be handled accordingly to the instructions in the database.

This site will become the central database sync server for all scarecrow modules (kind of like an antivirus definition update center).

At present I plan to add this module to my own ircd but I'll do my best to add support to unrealircd and others.

If you have any suggestions or ideas mail me to scarecrow@nix.co.il