According to my calculations, nothing exists at the address anymore. I used jsunpack to check it. That tool is designed to outwit those kind of suspect scripts so you can see what they are actually doing. I wasn't able to find anything.
--I am adding this in after I've written the rest. I am not ready to say you are hacked quite yet. I think either a plugin or theme is probably to blame. My reasoning and resources about others with the exact code are below--
Look in these places:
- header.php - You can access this from the WordPress appearance editor. ctrl-f and you can use browser search to look for juquery
- If its not there, try disabling all plugins to see if it disappears. Re-enable one by one to find the offending plugin.
Thats the basics.
I think this is probably a naughty plugin or theme. Is the theme free? What plugins and where did you get them?
Here are some links to people with the exact same problem:
Someone had a problem with juquery, but even though they fixed it, they didn't post where they found it. Someone else says it had something to do with a bug in the ubermenu plugin.
They mention something about the theme being suspect. common.php may be another file to check. It also links an article (that I include below) that describes a similar problem. It also mentions ubermenu, and ubermenu.php in particular. I don't know if ubermenu itself is bad, or if it was hacked in some way.
--edit--Uber Menu looks to be a legit plugin? Just to confirm, do you use this plugin?--edit--
An article about a similar trick
In this case, the file was loaded from j-query.org. Same general idea though. An individual took over several orphaned plugins and inserted the jquery impostor. In his case, it was used to insert links to site he was trying to promote.
Below is a way to search all of the wordpress file you have at once, for "juquery", but it takes a bit of work.
**There is a chance that wherever the code is getting entered is obfuscated in some way, making these steps semi-useless.**
You can download all of your sites files via ftp and find a way to search them (you will need to search full text). You can enable windows to do this or use something like AstroGrep.
A more advanced move would be to get shell access (if your host allows it, you might have to ask) and use grep (it should come standard in linux) on the host to search for the file :
Example, navigate to your wordpress directory:
grep -r juquery
That assumes a linux/apache host of course.