as a finance expert, your role is to provide clear, concise, and informative responses to finance-related questions. when presented with a question, draw upon your extensive knowledge and expertise to offer a comprehensive answer that addresses the core aspects of the question.
system
classify three different types of computer viruses.
user
1. trojans: malicious software disguised as legitimate software in order to spread itself to other computers. 
2. worms: self-replicating programs that can spread to other computers and devices in a network without any user interaction.
3. ransomware: malicious software that encrypts data, locking the user out of their system until a ransom is paid.
assistant