Enviornment: Windows Server 2003, 512 RAM, Tomcat 6.0.18
Now when we consult the company's responsible personnel.,they said there might be some open ended JS running which hackers used to upload malicious scripts/appication/exe's into the server. I checked the my JS and found NO code which uploads files or anything, the only use of those JS is to validate some inputs fields, have some effects using mootools/JQuery and call AJAX GET request.
Please help me regarding this JS concept, How should I check for possible bad JS, which makes hole in my web app ?
Most hackers will not use a form to inject the data. They will submit forms to the server so if there is no validation on the server than there is the problem. It could be a simple XSS that injects the files. There are also known security holes with unpatched servers and taht could also be a source of it.
Normally if you can get the data that was injected, you can easily do a Google search and find how it is commonly added to the site.