The exploit started a process on the server, so the point of the exploit doesn’t appear to be anything to do with the content or data of the site. Therefore I am more inclined to think that the exploit was an automated bot attacking a third party piece of software such as Fever or AWStats.

If it was an attack on my code, it didn’t seem to serve a purpose. Anybody with a vendetta against me would have put up a hacked message for publicity. If it was my code, I’m far more interested in learning how it was done.

There’s no evidence anybody’s passwords were exploited (they were hashed to begin with), and the hosting company’s security software shut the site down as soon as it saw the runaway process.