My master’s thesis’ results will be published without my consent. What should I do?
Part of the results I obtained were published in my master’s thesis, which was submited via an online tool to my university; so there is proof that that work is mine, I guess.


Let me first say a meta comment - once you publish a set of results, they are no longer 'yours'. They belong, in part, to the institution that funded you, to your advisor who helped you write your thesis, and to other coauthors/colleagues who helped you along the way. Research is a collaborative act. 

To your specific case, I strongly doubt that you have proprietary rights to the data. You got the results as part of a Master's thesis supported by an academic institution that has rights to the data. What's more, once you published your thesis, anything in it can be used in future publications if it is properly credited (for example, if the dataset was published as an addendum to your thesis, it's fair to use it). That's basically the essence of academic progress. 

Just like any other idea that appears in your thesis, the moment that you decided to publish it (as opposed to, say, patenting it and starting a company to commercialize it), others can cite it and potentially use parts of it in their work (doesn't even have to be the advisor, literally anyone can). 

If the data is not published, I still argue that you could possibly be in the wrong in this case as well. From a proprietary perspective, you did not work alone. Your advisor and academic institution supported you, offered you tools (free access to software to develop your tools, access to your advisor, an office, classes you took, perhaps a laptop and computing services etc.). It is unethical (and a bit selfish) on your part to ignore all of the effort put into your thesis by others, and withhold the work from being published. 

See a similar discussion here.