FYI. Hack info in case it may be useful to others. I am still chasing this down.
I have found the attached PHP files in my Joomla site that will stuff my template's index.php with hundreds of ad links wrapped in a div with display:none. My robots.txt had been modified, deleting the line "Disallow: /includes/" and a new IMG folder was created under "incluldes" with tons of PHP files that generated these ads. I have attached a RAR file of the offending PHP files that I found in the system (folder structure intact).
When the exploit hit, I was running J 1.5.12 and had not upgraded to 1.5.14 yet.
Interesting, I have observed that the free/demo version of Firewall will run on my localhost, but not on my livesite. "Perform System Check" shows activity bars, but returns to the same screen without any results. Any thoughts?
Attachment exploit.zip not found