Signals intelligence
Signals intelligence intercepts alerted the Gestapo and SD to the "Red Orchestra", the Soviet spy ring in Germany. Schellenberg led extensive efforts over many months to identify the participants. 116 were arrested by the Gestapo, half of whom were executed following intense interrogations. By this time, Schellenberg had become a general ("Brigadeführer") in the "Allgemeine-SS" (General-SS). The operation was a major victory for the RSHA at the expense of the "Abwehr", who had been oblivious to the Soviet operation. Historian Klaus Fischer asserts that Schellenberg's "only major success was smashing the Red Orchestra."