CGI Script Security Hole Fix

I run a site called <[login to view URL]>, which allows users to create forms, quizzes, etc. and emails results to users. Recently, the site was used to send out thousands of spam emails, and my hosting company shut it down. I programmed all CGI's myself, but don't have the know-how for fixing this problem. The hosting company is [[login to view URL]][1], and is not giving me more information than "someone is using your program to access our mail servers to send out spam." This is an urgent project, and needs to be taken care of ASAP. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform UNIX