Ransomware is a type of cyberattack where malicious software encrypts an organization's data, making it inaccessible until a ransom is paid to the attacker. This aligns with the question’s scenario, where denial-of-service is caused by malicious data encryption.

Let's analyze the options:

A. Phishing:

Phishing is a social engineering attack that tricks individuals into providing sensitive information, such as usernames, passwords, or credit card numbers. It does not involve encryption or direct denial-of-service.

B. Ransomware (✅ Correct Answer):

Ransomware encrypts critical data and demands a ransom for its release, effectively causing a denial-of-service scenario since the victim cannot access their own systems.

Some well-known ransomware attacks include WannaCry and NotPetya.

C. Hacking:

Hacking is a broad term for unauthorized access to systems but does not specifically refer to denial-of-service through encryption. Ransomware is a specific type of hacking attack.

D. Malware:

Malware (malicious software) is a general category that includes viruses, trojans, worms, spyware, and ransomware. While ransomware is a type of malware, not all malware encrypts data to demand ransom.

IIA Global Technology Audit Guide (GTAG) – Auditing Cybersecurity Risks – Discusses various cyber threats, including ransomware.

NIST Cybersecurity Framework (CSF) – Defines ransomware as a major threat that disrupts business continuity.

COBIT Framework (Control Objectives for Information and Related Technologies) – Addresses risks associated with ransomware and how internal auditors should assess controls.

ISO/IEC 27001 – Information Security Management Systems (ISMS) – Identifies the importance of cybersecurity measures to prevent ransomware attacks.

IIA References: