Is it against discord TOS to ask someone their age if you believe they are under 13? It is NOT against Discord ToS. However, if they don’t want to verify your age, you can either threaten a report to discord tos, and kick them if you can.
Through a corrupted installation file Discord allows its users to modify JS files. This also means that a hacker can inject the code to the Discord client files if they somehow obtain the user’s login credentials.