Basically, not much. The Soviets evacuated the bulk of their industry and the associated personnel, and destroyed most of what had to be abandoned.

This meant all the Germans were left with were people. Some cooperated (and some of them are now idols in Ukraine and the Baltics), others were acquired as forced labourers. However, the NKVD had mostly butchered all the inmates before leaving, putting yet another spanner in Abwehr's works.

Combine that with a massive resistance movement coordinated from Moscow, and you probably get a net-negative.