I have not seen this before, so this is speculation based on circumstantial evidence - but I suspect speculation is about as good as we are going to get without knowing the name of the trojan and further details (for example IP addresses associated with those URL calls).
It would appear that this has something to do with "local.com" and an advertising "solution provider" they own called Octane 360. (See here). My guess is that this advertising agency is serving up malware. Whether it is serving it up and using your computer to help (which might be the case if the script you deleted handles those parameters and the IP's hitting it are from the wider Internet) or if Google or another bot is checking the site for Malware and using that as a clue to help you track down the cause (in which case the referer line in the log might give you a clue) can't be determined with the information at hand.
It is impossible to say whether they have left behind something - you would really need to work out how they managed to inject the code into your site in the first place and eliminate that vector. Depending on the vector you would need to take a view as to how much damage they could have done, and what exactly they could have modified, and then check for that.
As an RBL has been intimated, you should check your IP address and domain name against a multi-RBL checklist to see if its blacklisted and take steps to "unlist" it if it is. This could also provide a useful hint as how the site was compromised if the RBL provides further information.
Realistically, unless you have the knowledge to track down what they did and how they did it, you should call in a professional to help - no one can realistically provide an answer to you without a lot more knowledge of your particular environment and circumstance.