DeFi Detectives: Chef Nomi Investigation Notes

Last week I had a lot of fun with the latest blockchain investigation competition put together by folks at Anchain. The competition spanned two weeks and included a number of questions challenging players to dig through Ethereum blockchain transaction and smart contract data. In addition to many freely available tools, participants were also offered a free license of Anchain’s CISO blockchain analytics platform which made the analysis a lot easier.

In this writeup I will discuss blockchain analytics tools, techniques, and lessons learned while solving challenges. I will only focus on solving the last (and hardest) challenge investigating the infamous exit scam and the eventual return of funds by SushiSwap’s Chef Nomi back in September, 2020. My goal is to share the investigation steps so that you, the reader, would also be inspired to participate in future contests or may be even make this your future career. Check out my Blockchain Threat Intelligence newsletter for ideas on how to contribute to this field. If you would rather see the solution and investigation files, just scroll down to the report section of the article.

Here is the challenge question:

On September 5th Chef Nomi, the original creator of SushiSwap, cashed out around $14M from SushiSwap and gave it back on September 11th. Can you find what…