In reply to:
And the only forms I have are for asking for site link exchanges, and I don't get anywhere near 200 a day. Heck, 200 a year would be more like it, you know? Those forms all get sent to me, so I am able to keep tabs on how many of those are sent out.
I think you are missing an important concept here. An exploited form *will not* behave as you , or the author, expected it to: It has been "owned" to a greater or lesser degree, and you have *no idea* whether or not they "get sent to you", or "how many are sent out".
In reply to:
None of my sites have nearly enough visitors to hit the 200 in an hour mark
Not to belabour the point, but, again, a single "visitor" (who exploits one of your forms to send 10, 50, 100 emails *at a time* via your compromised/exploited form) may be what you are dealing with here, and pumping out *only *3* emails "in an hour" from each of your subdomains will result in the DH user having "sent" 300 emails. Without viewing your logs or your stats, how do you even know how many "visitors" you have?
In reply to:
Stats and logs, huh? I'm going to go find those in my webpanel and get to the bottom of this.
The wiki is a better source for learning how to get at this, as your stats directory and log directories are in your "home" user space reachable by ftp (or ssh to reach the shell).
Do you use the same form handler on all your domains/subdomains? If so, point us to it and we can check to see if there are known/published exploits for it.
It *might* also help if you published your site's url (or if you would rather not publish it but would like me to look at your site, just PM me with the info).
I'll have to be honest with you though, if all your forms are for setting up link exchanges, and you are using "over 100" subdomains, you probably have a real mess on your hands. I wouldn't be *at all* surprised if some "link exchange script" was set up to be backdoored for exactly this purpose by a ,er, "less than honorable" SEO gamer who plasters the web with his "owned" script, and then "slams" the sites using it to send spam. It has been known to happen...
--rlparker