Telegram and discord webhooks are 100% signs of an unsophisticated attacker and they are a very common sight in malware samples. Github is full of skiddie "info stealer" projects that use telegram api / discord webhook to deliver the stolen data. They make no sense to use since anybody can spam that webhook endpoint. Not 100% sure about discord, but at least in the case of telegram anybody can even read and download all the data that has been sent to it.