Thanks. I checked and they seem to be legit.
And I've also logged into my account and confirmed the Copy button is not compromised (i.e. copied address is the same when pasted).
There's a chance your system has been compromised. Run a malware/ spyware scan on your system using some tools like Malwarebytes and check if anything shows up.
Right, follow this instruction from @UserU, your system was compromised and the only solution is to remove it. If you still failed to found the malware and the problem still occur, try to reformat your personal computer and start to avoid installing unnecessary applications including chrome extensions.