Is looking up the source of tests and using those to practice considered cheating? The question (Is studying past exams I found online cheating?) was sort of relevant but did not answer my question, so please do not mark this question as a duplicate:

Onto my dilemma:

I recently had a raw score 20 points higher than my classmates and was suspected of cheating. I scored almost perfect while others only got around 60-75. I actually found the test beforehand (coincidentally) because my teacher passes back old tests and quizzes (and his sources are obvious). I sought online materials because the textbook and the practice problems are utterly inadequate for relatively difficult exams. I know it gives me an advantage, but couldn't everyone just do what I did? Don't I have the right to study things that are openly accessible on the web and use that to my advantage? It's not like I hacked a school server to access materials.. I literally just found it by using some google search 'hacks' like verbatim, quotes, filetype, etc. I ended up not getting a score for that test, but did the teacher really have to do that? I didn't even copy the test word-for-word. I knew how to do most of it and just used it to make sure that I knew what I was doing. I am currently under a lot of backlash due to this incident and am trying to justify my standing. What are your thoughts and what prevents me from using those sources? 

Clarification: it was not even the teacher's own test.
No, that is not cheating as the comments point out. You have invested time looking for material to practise and come across some. However, if you had to “hack” a system to get the test that is a different case.... :)

The “cheating” or , at least poor practice is from the teacher just taking and using verbatim a test from somewhere - editing, changing questions, changing numbers is often done to make a new or suitable version.

Using a test from somewhere else may be ok, but all the questions need to be checked : vocabulary, level etc before use and adjusted as necessary.