This report by the Center for Human Rights in Iran (CHRI) incorporates independent and original research undertaken by CHRI’s internet security researchers and analysts during the period from January 2017 to January 2018. CHRI conducted detailed technical analysis of Iran’s National Internet Network (NIN) and its various tools and services, including the national operating systems, browser, search engines, emails services, mobile applications, and other software; the tools and methods used in state-sponsored hacking attacks (DDoS, phishing, malware, message interception and fake applications); and the accounts of state-sponsored hacking victims. CHRI also incorporated extensive interviews with approximately 26 Iranian information and communications technology professionals, journalists, activists and other members of civil society in Iran who have been the victims of state-sponsored hacking attacks. The interviews were done via secure online platforms during the period from February 4, 2017 to February 14, 2017. CHRI also undertook a comprehensive review of Iranian state policy, legislation and practices regarding internet access, censorship, surveillance, cyberattacks and the development of Iran’s National Internet Network, as well as public statements by Supreme Leader Ali Khamenei, President Rouhani, his cabinet and other administration officials, Parliamentarians, judicial officials, Islamic Revolutionary Guard Corps’ (IRGC) members, and leading state -affiliated clerics, as reported in the Iranian press and on the websites of those officials. CHRI also consulted with leading international internet freedom researchers.In particular, CHRI wishes to thank Collin Anderson, a Washington, DC– based researcher focused on cybersecurity and internet regulation, for his review of and assistance with this report. This report incorporates the research contained in, and is a follow up to, CHRI’s November 2014 report, “Internet in Chains”: The Front Line of State Repression in Iran.