Since too much stuff is falsely called Torah it occurs to me to make a short list of what counts as authentic Torah. [As the Rambam wrote Just like there is no adding or subtracting from the Written Law so there is no adding or subtracting from the Oral Law. The Rambam goes into this in his letters. 

So the list is the two Talmuds and the Halachic midrashim and agadic midrashim. 

Mechilta, Sifra, Sifrei, Midrash Raba, Midrash Tanhuma, Eliyahu Raba, Eliyahu Zutra, Tosephta, the shor mesechtot printed in the end of the Villna Shas.

But I would have to include in the commandment to learn Torah the commentaries, though not actually "Torah" still they are a part of "learning Torah."

But even in later commentaries, there is some point where things cease to be Torah and start to be Fraud.[Of course that was the reason for the signature of the Gra on the letter of excommunication.]