I worked with a fake SSN pre-DACA. I think most of us are aware that it's common practice in the undocumented community. I think the government is very aware of that fact as well; just look at the IRS issuing ITINs. And if I remember correctly, when I went to get my new SSN after I was first granted DACA, the Social Security Administration employee informed me that I could transfer all social security benefits I had accrued using other SSNs to my own.

I honestly don't think it impacts your chances to adjust your status one day. I say this because I have a few family members that also worked with fake documents and were able to get green cards without a problem.

Now, I do have to agree with others that these are tense times and using a fake SSN could be riskier now than it was back in my day. If you can, try to find self-employment work, where you can get paid by cash/personal check. I know it's hard to build a steady, stable income this way, but this is for sure the safer route you can take.

I remember very well how hard it is to attain substinence without a SSN, so I completely understand your situation. If using that fake SSN is the route you have to take to survive, then that's the way it is. Just be aware of the risk. Back when I was doing it, I would regularly get letters from the Social Security Administration warning that the number I was reporting didn't match my name. Eventually one of my employers got one of those letters and they had to let me go. The SSA doesn't report to ICE, but they will be aware that things don't match up.