For those who worked with fake SSNs

I started working at a job years ago with a fake SSN, it's a crappy restaurant job but i get paid decent.. anyway, i told them about my situation and they were happy i got my EAD and even offered me a higher management position since i've been there so long.. so they told me that it is possible i can fill out a form so that they can change my SSN from my fake one to my real one within the company. My question here though is.. will that affect me later when i want to adjust my status? To me that really seems incriminating to tie my old ssn to my new one. Thanks in advance to anyone who can help.

it doesn't matter cause when you adjust you'll have to admit that you used a fake ssn before and if you don't, it's not hard for uscis to find out