A cyberattack that seeks to make a machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a host connected to a network. This is typically accomplished by flooding the targeted machine or resource with superfluous requests in an attempt to overload systems and prevent some or all legitimate requests from being fulfilled. The range of attacks varies widely, spanning from inundating a server with millions of requests to slow its performance or with a substantial amount of invalid data, to submitting requests with an illegitimate IP address, and launching "low and slow" attacks aimed at keeping connections open.
In a distributed denial-of-service attack (DDoS attack), the incoming traffic flooding the victim originates from many different sources, often making it harder to block or mitigate. A type of cyber attack in which multiple compromised computers or devices flood a target system or network with massive traffic, overwhelming its resources and making it unavailable to legitimate users.
How a DDoS Attack Works
- Attacker controls: A network of infected computers, known as a botnet, which are often compromised without their owners’ knowledge.
- Bots send: A flood of requests or data packets to the target system, overwhelming its capacity to handle legitimate traffic.
Common DDoS Attack Techniques
- ICMP floods: Sending a large number of ICMP Echo Request (ping) packets to the target system.
- SYN floods: Exploiting the TCP handshake process to consume server resources.
- UDP floods: Sending a large number of UDP packets to random ports on the target system.
- HTTP floods: Overloading a web server with a high volume of HTTP requests.
- DNS amplification: Exploiting open DNS resolvers to amplify the volume of traffic sent to the target.
Impact of DDoS Attacks
- Financial losses: Significant financial losses due to downtime and lost productivity.
- Reputation damage: Damage to a company’s reputation and customer trust.
- Service disruption: Disruption of critical online services, leading to slow response times, unresponsiveness, or complete shutdown.
Mitigation Strategies
- Traffic filtering: Identifying and blocking malicious traffic.
- Rate limiting: Controlling the number of requests a server will accept.
- Dedicated services: Using specialized DDoS mitigation services or appliances to protect against attacks.
