Ransomware is a type of malicious software (malware) that develops within an ecosystem combining criminality, cyber espionage, and disinformation. In concrete terms, an attack begins with an intrusion, and then spreads inside the computer system via computers, servers, telephones, routers, and other connected objects. Some groups develop malicious tools, others sell compromised access to computer systems, or provide ransom negotiation. For that matter, ransomware groups do not always carry out the attacks themselves, often relying on affiliates who are compensated according to the success of operations. Computer systems sometimes contain design errors that can be exploited to gain access.