Most of the ways I know where people make millions without hardwork are illegal and frowned upon. 

The only legal way I know of is through investing.  You invest a particular sum of money for an extended period and it grows at an exponential rate without you lifting a finger. 

One of such investments is real estate investment where you buy a piece of property and it increases in value the longer you leave it. 

You could also invest in shares,  bond,  etc to get the same value.