Which program is this: 4MNPdKu9wFMvEeZBMt3Eipfs5ovVWTJb31pEXDJAAxX5?

Question

I was trying to transfer a token from Wallet 1 -> Wallet 2 using sollet.io on testnet.
It showed this error:

failed to send transaction: Transaction simulation failed: Attempt to load a program that does not exist

I inspected the network call and got the base64 encoded transaction and pasted it on https://explorer.solana.com/tx/inspector

It showed that a call was being made to this program (https://explorer.solana.com/address/4MNPdKu9wFMvEeZBMt3Eipfs5ovVWTJb31pEXDJAAxX5) which doesn't exist on testnet, but it does on mainnet.

Does anyone know which program is this?

Here's the screenshot of the decoded instructions:

Answer 1

It's a deployment of the Serum assert-owner program. Google can be surprisingly revealing of unlisted program IDs