Which of the following best describes Ransomware?

Ransomware is a type of malicious software specifically designed to interfere with the access to a computer system or its files, typically by encrypting data. Once the data is encrypted, users can no longer access their files, leading to significant disruptions in operations. The attacker then demands a ransom from the victim to restore access to the data, often threatening that the files will be permanently lost or published if the ransom is not paid.

This characterization highlights the operational impact ransomware has on victims in the marine safety sector and beyond. Understanding ransomware's nature is critical for marine safety personnel, as it can lead to major operational risk and safety concerns if vital systems and data become inaccessible.

Other options address separate cybersecurity concepts: detecting vulnerabilities pertains to security audits and assessments, search engines have no direct relation to data security but rather information retrieval, and denial of service attacks are aimed at overwhelming a system to make it unavailable, rather than specifically targeting data encryption like ransomware does.