Attack

In cybersecurity, an attack is an attempt to gain unauthorized access to systems, services, resources, or information, or to compromise confidentiality, integrity, or availability. Attacks can also involve malicious efforts to collect, disrupt, deny, degrade, manipulate, or destroy information-system resources. An attempt can qualify as an attack even if it ultimately fails.

A cyber attack can include malicious activity intended to access, disrupt, disable, alter, control, or damage a computing environment or its information. Examples include credential attacks, malware, denial-of-service activity, exploitation of vulnerabilities, and unauthorized access attempts. The defining feature is hostile or unauthorized action against the system or information, not merely a software defect.

A vulnerability is a weakness that could be exploited, while an attack is the action or attempt to exploit, bypass, disrupt, or compromise a system. A system can have vulnerabilities without being attacked, and an attacker can attempt an attack without succeeding. Countermeasures aim to reduce vulnerabilities, block attacks, or limit their impact.