A cyberattack called “attack on availability” is one that seeks to impair normal access to systems, networks, or information. Rather than stealing or altering information, the attacker aims to render services slow, unreliable, or entirely unavailable to legitimate users. This directly targets one of the three foundational pillars of cybersecurity—availability—by denying organizations and people access to the resources upon which they rely. It is very interesting how it all works and how individuals do it.
A common example that is occurring more and more often is the Distributed Denial-of-Service (DDoS) attack. In a typical DDoS attack, an attacker uses tens of thousands or millions of compromised devices to send a flood of traffic toward the target. The traffic overloads the target system’s bandwidth or processing capability, and the service crashes or is unreachable. Reports show that a number of recent DDoS attacks have reached unprecedented borders, even terabit-scale floods that have temporarily taken major organizations offline. These trends commonly target public-sector government agencies, online financial platforms, and high-traffic online businesses that have a significant dependency on being available 24/7.
The consequences of availability attacks go well beyond short-term inconvenience. For organizations, downtime results in financial loss, diminished trust in their customers/businesses, harm to their reputation, and disruption to their business operations. For critical sectors such as healthcare, transportation, and public services, failures of availability may create significant risks to safety. Users may lose access to essential services that include online banking, communication tools, and medical resources. In response to these threats, organizations’ best defense is layered defenses such as traffic filtering, including redundancy, cloud-based mitigation, and monitoring. Maintaining a secure availability is important for stability in operations and sustaining trust in an organization’s operations.

Resources:

Cloudflare DDoS Threat Report 2025 Q2: https://blog.cloudflare.com/ddos-threat-report-for-2025-q2/
Infosecurity Magazine – ENISA DDoS Findings: https://www.infosecurity-magazine.com/news/hacktivistdriven-ddos-attacks/