So I am just concerning is it legal to DNing in Malaysia with Tourist pass?(they call it social visit pass)
Your Social Visit pass is for social visiting the fine social people of Malaysia. If Immigration asks tell them you are there for a Social Visit and maybe some Tourism as well.
Telling them you are there for work won't go down well.
You enter as a tourist and leave as a tourist. That's it.
It is illegal to enter as a tourist and work as a DN in any country.
Had you worded your question like: "Will I be OK if I say I'm a tourist and actually work as a DN?", the answer would've been: "No worries, everyone does that, you'll be fine".
Never say the words "I am a digitial nomad" or "I am a remote worker" at immigration or you will have a bad time. You are a tourist.
Actually, the 3-4 times I've been to Malaysia they have barely asked me anything.
They're not worried about westerners working tbh. Just say you're a tourist visiting and you're good to go.