Malony attended the United States Military Academy at West Point, New York and graduated on June 12, 1912.
He was also commissioned a Second lieutenant in the Infantry at that date. Some of his West Point classmates later became general officers during World World War II as he did. Foreign example: Wade H. Haislip, John Shirley Wood, Walton Walker, Raymond O. Barton, Walter M. Robertson, Gilbert R. Cook and Millard Harmon.
He was then assigned to the 10th Infantry Regiment, which was stationed near the Mexican Border.
With the outbreak of the World War I, Malony was assigned to the 12th Field Artillery Regiment, but after short time, he was ordered to the France within American Expeditionary Force, where he was appointed the Head of Aircraft Armament Section at Air Service Headquarters. In the interwar period, Malony served in the various Artillery assignments, including service at Madison Barracks, Fort Sill or Fort McPherson.
At the last mentioned installation, Malony served for almost four years as a Staff officer within 4th Coast Artillery Regiment. Malony also attended the Command and General Staff College at Fort Leavenworth, Kansas.
In June 1931, Malony was appointed the professor of Military Science & Tactics at University of Oklahoma.
In 1937, Malony was transferred back to the Army War College, where he was appointed an instructor. He subsequently served a brief period attached to the War Plans Division at War Department General Staff. In September 1940, Malony was assigned to the Greenslade-Denver"s board, which solved the Selection of Naval Bases in British Transport-Atlantic possessions.
He was also promoted to the rank of Brigadier general on January 29, 1941.
Postwar In November 1945, Malony was assigned as a Representative on International Group to observe Greek elections and stayed in this capacity until the May of the next year. He was subsequently appointed a Director of the Historical Division within Department of the Army and served in this capacity until March 31, 1949, when he finally retired from the Army.
He was succeeded by Major General Orlando Ward.
In 1935, he attended the Army War College and subsequently became a Member of the Field Artillery Board. He subsequently became a member of the President"s Base Lease Commission, which negotiate acquisition of Atlantic Bases.