Q. What is the frum position when it comes to the fraternal organizations such as the Freemasons?

A. The claim of some that the origins of Freemasonry go back to the days of King Solomon, Hiram of Tyre, or even Lemech is indeed doubtful or at least hard to prove. However, some distinguished Jewish personalities throughout the ages were Freemasons, such as Sir Israel Brodie Chief Rabbi of England and Grand Chaplain of the United Grand Lodge of England and others.
Horav Shlomo Miller Shlit’a pointed out that even though from its inception Freemasonry lodge constitutions reflected religious tolerance, in practice, in Germany and even in England there was discrimination and few Jews were admitted during the eighteenth century. (See Encyclopaedia Judaica).
Although, at least in principle Freemasonry does not consider itself a religion, it does demand a belief in monotheism. In reality, some lodges have in the past exposed a tendency to Christianity.
Some lodges may be formed by a large membership of active practitioners of other religions and their beliefs may permeate the laudable charity and benevolent work they do. Other lodges may be totally Jewish, but not necessarily comprised of Torah observant members. Working and associating closely with them, even for praiseworthy philanthropic and altruistic undertakings, may not be the best way to advance in bettering oneself in Torah and mitzvos observance.
Therefore, Horav Shlomo Miller’s Shlit’a opinion is that given that there are many Torah observant institutes that promote excellent chesed and help for the needy and require associates and assistants, when possible one should join them.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a