This is Gomorrah - Tom Chatfield

Darknets are everywhere - and those who know where to look can find anything. Drugs, guns, porn, ideologies, lives and deaths are all up for sale and everything must go. Elite hacker, loner, charmer, idealist and connoisseur of other people's mistakes, Azi Bello exists in a world where the dark side of technology is abolishing the old order - and he has a front row seat. When the secretive but intriguing Munira reaches out to Azi for help, her story sparks his interest. Munira's cousin has been recruited to work for a terrorist state and in her attempts to find out more, she has attracted the attention of some very dangerous people. As they work together, Azi and Munira are drawn into an unimaginable conspiracy, at the heart of which is Gomorrah: an exclusive online marketplace where anything can be acquired and the world's worst individuals lurk. As he throws himself into uncovering Gomorrah's dangerous secrets, it isn't long before Azi's carefully constructed world begins to fall apart - and he is forced to become much more than just a spectator. But when identities can be changed with just a few clicks can you ever really trust anyone?