King Farouk was not assassinated, he was overthrown by Nasser & Co and went into exile. The MB did not install Nasser, who regarded them as a mortal enemy, he and his fellow colonels engineered a takeover which insured more or less that Egypt would continue as a secular nation.
Nasser was a world class jerk when it came to foreign policy, but a Muslim Brother he has wnot.
this from Jewish virtual library on MB
In 1942, during World War II, Hassan al Banna set up more Brotherhood branches in Transjordan and Palestine. The headquarters of the Syrian branch moved to Damascus in 1944. After World War II, Egyptian members took violent action against King Farouks government. When the organization was banned in Egypt, hundreds moved to Transjordan. Many also participated in the Arab-Israeli War of 1948-1949. The Egyptian Muslim Brotherhood initially supported Gamal Abd an-Nasser's secular government and cooperated with it, but resisted left-wing influences. A Muslim Brother assassinated Egyptian Prime Minister Mahmud Fahmi Nokrashi on December 28, 1948. The Brotherhood was banned, and Al Banna himself was killed by government agents in Cairo in February 1949. Thanks for the correction-