Imagine

Someone codes some utility, but not copyrights it or adds any license. Some company steals the code releases it as commercial closed source executable and then sues the original author for copyright infringement. Is this possible?

>>1
In most places it is difficult to avoid copyrighting something you write.  Just by writing it, you automatically have copyright.  In the US, there are only a few ways to get rid of copyright: give it to someone else, wait until seventy years after you die, or write things as part of your government job.