Endlessh periodically sends data so the read timeout won't trigger. Specifically, it draws out the crypto negotiation stage indefinitely by exploiting a feature

Endlessh periodically sends data so the read timeout won't trigger. Specifically, it draws out the crypto negotiation stage indefinitely by exploiting a feature of the SSH protocol. (Of course, the bot author could detect that behaviour too.) There's more info from the author of Endlessh: https://nullprogram.com/blog/2019/03/22/ https://nullprogram.com/blog/2019/03/22/