Using proxy it's not possible to bypass an internet blocking virus
There are certain malware variants that are capable enough to replace your browser's configuration with their own malicious server, modifying your DNS settings, and adding entries in the host files of your operating system.
As a result of which, you might face redirecting issues or get your internet connection totally blocked. Therefore, you will not be allowed to access any websites and download the software to reduce security infections, irrespective of what URL you enter in the address bar.
How to Troubleshoot
It's important to kill them, otherwise, they will continue to reproduce these files and cause issues
To start, try and boot your system in safe mode with the help of networking.
Mostly, you will be able to connect to the internet.
Attempt to download a suitable one that can kill all the processes that are connected with the virus. Download it, run it, and wait till the program has done its work. You must see that some viruses will attempt to remind you that the antivirus program that is running is an infection. You can,ignore it.
After completing all the above steps, do not reboot your system. You must first ensure that you have considered all the follow-up steps as well, even a full scan.
You should also ensure that your system is guarded with a secure and updated antivirus program. Irrespective of whether you are using proxies or not, it is vital to avoid accessing websites that are malicious, downloading unnecessary software etc.