On 4 May 1946, all the counterintelligence structures of SMERSH were renamed The Third Main Directorate of the Ministry of State Security. SMERSH - founded in late 1942 by Joseph Stalin as a portmanteau of the menacing words Smert Shpionam (Death to Spies!) - became a thing of the past.
There were a total of three organisations under that name. By a secret resolution - No. 415-138ss of the Council of People's Commissars of the USSR of 19 April 1943 - the Main Counterintelligence Directorate “SMERSH” of the USSR People's Commissariat of Defence, and the Counterintelligence Directorate "SMERSH" of the USSR People's Commissariat of the Navy were established. On 15 May 1943, the Counterintelligence Division (OKR) of the USSR NKVD was created by order No. 00856 of the USSR NKVD for the gathering of intelligence and operational services of border and interior troops, police and other armed formations of the People's Commissariat for Internal Affairs.
The main adversaries of SMERSH were the Abwehr, the Reich Main Security Office (RSHA) and the Finnish and Romanian military intelligence services. Service in SMERSH was extremely hazardous – an operative served an average of three months and was then discharged either because of death or injury. SMERSH carried out a preliminary security sweep of the front lines from German agents and anti-Soviet elements. SMERSH was particularly successful in radio surveillance.
Each military unit had a SMERSH officer who monitored soldiers and officers with problematic backgrounds while recruiting agents. SMERSH created and maintained an entire system of surveillance of citizens in the interior and at the front.
SMERSH counterintelligence agencies had no procedural status, so detainees were interrogated and sometimes shot extrajudicially, “according to wartime law”. Even high-ranking officers could be detained for several years, again without trial.
“Military counterintelligence SMERSH during the Great Patriotic War: Death to Spies!” by Alexander Sever