1. Botchain. https://botchain.network/
2. Identify Chinese cyber espionage group. https://tinyurl.com/pntdm64
3. A web about op$$\_$$return. https://opreturn.org
4. Adair, S., Deibert, R., Rohozinski, R.: Shadows in the cloud: investigating cyber espionage 2.0. A joint report of the Information Warfare Monitor and Shadowserver Foundation (2010). http://shadows-in-the-cloud.net
5. Ali, S.T., McCorry, P., Lee, P.H., Hao, F.: ZombieCoin 2.0: managing next-generation botnets using bitcoin. Int. J. Inf. Secur. 17(4), 411–422 (2018)