I have configure the proxy server. (non transparent proxy) now when i download a test virus from a http link it is scanned and blocks the file. When i download the file from https it does not scan the file and does not block the file.
How could i resolve this, and let it also scan https?
I think you have also activated clamav.
Squid (and the helpers squidclamav, URLFilter, … ) cannot analyse the content of encrypted data packets which flow in HTTPS connections ( see man-in-the-middle ).
These attacks can be detected at the endpoint of the HTTPS connection only, the client in the local net.