Born 1919 in Kovno (Lithuania) and studied at the Kovno Reali High School. Active in Betar. In 1938 immigrated illegally to Eretz Israel in the Af-Al-Pi project and joined the Beter company at Rosh Pina. Shortly afterwards joined the Irgun.

In 1944 was transferred to Jerusalem as deputy to the District Commander, Eliyahu Lenkin. After Lenkin's arrest, Efrat was appointed in his stead.

In August 1945 , he was arrested by the British, and a body-search revealed a slip for a parcel to be collected from the Atid taxi company. The parcel, containing detonators sent from Tel Aviv, served the prosecution as evidence at his trial before a military tribunal. He was convicted and sentenced to seven years imprisonment.

Freed two years later by his comrades during the Acre jail break.