Datalog Geological Services interview questions

I applied online and got a call from them. They explained the position, benefits and general duties. They asked me if I was interested and I said yes. I didn't hear back from them so I emailed and got another call. They told me the same information as before and I said I really wanted the position as I was in another interview process but I preferred this position. They sent me an email the same day with the job offer letter and other documents to sign. I signed them and sent them back along with my driver license and SS card as they had asked for. Nothing else from that moment. I have sent around five emails asking how was the background process going but nothing. I even tried to call but couldn't reach anyone. No I'm even worried it can be a scam to steal my identity as I even sent my SS card, full name, and address.