Which of the following best represents the concept of crypto-malware?
1) Software that secretly captures and transmits a user's data, credentials, passwords, or usage behavior.
2) Software that encrypts data and offers a decryption mechanism after payment of a ransom.
3) Malware that spreads copies of itself to other computers when it is executed by a user.
4) "Ambush" malware; code that waits for a particular event or circumstance to occur before it executes.
