I'm sorry, I'm not sure if I fully understand. Are you saying that this script is not malicious? Is this a false positive? Should I change all my passwords as recommended by avg support?
AVG SUPPORT's Reply
"I'd request to click 'Send for analysis' from AVG quarantine to submit the file for analysis.Click this link https://support.avg.com/SupportArticleView?urlname=Use-AVG-Quarantine on how to submit a quarantined file for analysis.It looks like a browser hijacker which is a form of unwanted software that modifies a web browser's settings without a user's permission, to inject unwanted advertising into the user's browser. A browser hijacker may replace the existing home page, error page, or search engine with its own.
As a precautionary measure, I'd recommend you to change the passwords and delete saved card numbers from any websites.It is unlikely that your personal information is stolen"