Will anyone know if you fail out of a master's program?
It may be that they would learn of it, or possibly not, but the consequences of them learning that you omitted something that they considered important could be dire. It would be treated as a mark of dishonesty and neither employers nor universities generally value dishonesty. 

The record exist and might come to view at some point, though they would, in most cases, not be sought. But you need an explanation for the time you have spent. If it is a black hole it looks pretty bad on your record, both for an employer and for a future degree. 

You are probably safer to just be honest. There may be reasons for failing out that others would consider valid. Academia isn't for everyone and many people have various struggles that make success difficult. 

If you have access to an academic counsellor, you should make an appointment and go. You may get good advice there about withdrawal and your future plans.