Hey there Oyinbra!
My name is Miguel Ángel and I'm an independent advisor, also a Microsoft user just like you! I'll try to help you today with your issue.
It is not detecting Powershell as a virus, but rather Powershell is trying to access a specific website that is trying to inject a trojan. It may be a script that you have downloaded or that is running on startup.
You should run a check with HitmanPro (https://www.hitmanpro.com/en-us), a check with MalwareBytes (https://www.malwarebytes.com/mwb-download), a check with AdwCleaner (https://www.malwarebytes.com/adwcleaner) and then a final check with MalwareBytes Anti-Rootkit (https://www.malwarebytes.com/antirootkit). You can run a final check with HitmanPro again, which is a very strict and exhaustive antivirus.
Let me know about the results.
I'll wait for your reply! Don't worry, everything will be okay :)
Note: This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it. All files have been analysed for malware with VirusTotal, and have shown a positive output, being completely safe to install.