By restricting the server and encrypting the data, a software company's server is unethically accessed in order to obtain sensitive information. The attacker blackmails the company to pay money for getting access to the data, and threatens to publish sensitive information unless price is paid. This kind of attack is known as :

1. Phishing
2. Identity Theft
3. Plagiarism
4. Ransomware

Ransomware

Reason — Ransomware is a type of malicious attack where an attacker gains unauthorized access to a system or server, encrypts the data, and demands a ransom in exchange for the information. In this scenario, the attacker is threatening to publish sensitive information unless the company pays the ransom, which is a characteristic of a ransomware attack.