From there, FIST proceeded to trace the accounts and transactions involved. With the assistance of the US Secret Service and the Internal Revenue Service, investigators concluded that Kvashuk had defrauded Microsoft, despite efforts to conceal his identity with fake accounts and to hide public blockchain transactions using a Bitcoin mixing service.
In addition to service provider records that point to Kvashuk, the complaint notes that Microsoft's online store uses a form of device fingerprinting called a Fuzzy Device ID. Investigators, it's claimed, linked a specific device identifier to accounts associated with Kvashuk.
Pretty involved dissection, went all the way down to digital fingerprinting to catch it.
The thief was smart about the hiding it, but not smart enough, but he had to know after $10m they would catch on. Reminds me of the McDonalds Monopoly game that the extended family of one of the people that worked at the printing place kept winning which was improbable, then expanded further where everyone would give them a cut of the winnings up to $24m [1].
> Jerome Jacobson and his network of mobsters, psychics, strip-club owners, and drug traffickers won almost every prize for 12 years, until the FBI launched Operation ‘Final Answer.’
Take $10m or $24m from a large corporation, someone is going to notice.
[1] https://www.thedailybeast.com/how-an-ex-cop-rigged-mcdonalds...