One solution to this problem is the yeshivas founded in the path of the Gra, i.e. straight Torah with no pretenses. However the demons have extended their reign so far as to enter, and sometimes even take over these basically good places. I personally have not found a solution to this problem except to try to learn Torah in my own space--as far as I am able--which is not very much.
[I might mention here that in fact I am not in a place where there is any straight Litvak yeshiva. If there was, I might very well change my approach and try to learn there. I have hear that there are extensions of Ponovitch in different areas. but I have not heard of anything like that near my area. Recently. I saw a group from the Aderet Eliyahu [based on the Gra] just visiting from Jerusalem, but so far I have not heard of any real presence of a Gra sort of yeshiva in this area. [I might add to learn the the Birchat Shmuel--also a disciple of Rav Chaim of Brisk and Rav Naftali Troup. I do not know of learning these could take the place of an authentic Litvak yeshiva but nowadays, learning at home might be the only possibility because the immense confusion that exists in the Torah world.
[I should mention that Torah scholars that are demons is a wide spread problem in the Torah world. It is almost impossible to avoid unless one learns at home. So what one might do is simply get some of the basic Torah books, e.g. the Chidushei of Rav Chaim of Brisk and learn at home.[Or the book of Rav Shimon Skopf, or the Avi Ezri.]
The Ari'zal [Rav Isaac Luria] says in this world the evil is the majority. So if one finds that someone is presented as a great tzadik, the likelihood is that he is a demon
should at least be taken as a possibility.