score:3
As the DS-160 form asks applicants to provide employment history for the previous five years, it would be an oversight to omit it. Although the company no longer operates, provide the last known address and phone number. In the section where you're asked to briefly desribe your duties there, at the end of that statement you might simply add that the company ceased operations in month/year. Consular officials understand that companies fold and would be able to verify that, should it be necessary. Not including the company leaves an untidy gap in your employment history and the application.