Potential security issue


I found out t hat there is infection on my site. I have done sucuri.net site checking and I am prompted with test result as on image below
I opened those files and I found that instead of content there was encoded script as presented on image above.
Please advise what might be issue that those two .js files are infected.

Hi @vvucic,

Those files don’t contain that code in the .tar.gz distribution; I suspect something has modified those files locally on your server.

Alec Smecher
Public Knowledge Project Team

I Know that this code is from malware injection. I found out that this could be

However, I am concerned about possible causes and potential vulnerability of jquery.js