"We learned a lot of lessons with DarkMarket, and we've passed that experience on not only to other offices within the FBI but to our counterparts overseas," Strom said. "We're definitely taking the fight back to them."
Hex Nightmare agrees the FBI may eventually make more progress. When Slavik, the author of the ZeuS malware, disappeared in 2010, he was at the height of his fame. Theories about his disappearance abound on the underground: Slavik was killed; he now works as a cyberspy for the Russian government. Hex Nightmare has her own: "I think Slavik thought it was a good time to get out."