What is the scam “UD” coin withdrawals onchain that mimic your USDC withdrawal values? How are they permissioning withdrawals and when no deposits?

I have a lot of scam withdrawals "UD 500" on ETH, POLYGON, BASE chains. They mimic USDC withdrawals, within an hour. I assume they are hoping you will copy the address from them but — how are they WITHDRAWING? It's not a scam token deposit, that's easy to do. How are they getting permission to WITHDRAW something, and notably, there is no deposit onchain. So is it just some glitch scam? or is this some kind of legitimate component I've not heard of yet? doubt it. Thanks.