Distributed Denial of Service (DDoS) attacks are malicious attempts to disrupt the normal traffic of a targeted server, service, or network by overwhelming it with a flood of internet traffic. This surge in traffic renders the service unavailable to legitimate users, causing significant disruptions.
Main Techniques Used in DDoS Attacks:
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Volumetric Attacks:
- Description: These attacks aim to consume the target's bandwidth by flooding it with massive amounts of data, overwhelming the network's capacity.
- Examples:
- UDP Floods: Attackers send a large number of User Datagram Protocol (UDP) packets to random ports on the target server, causing it to process unnecessary data and become overwhelmed.
- DNS Amplification: Attackers exploit publicly accessible Domain Name System (DNS) servers to flood a target with amplified traffic. By sending small queries that result in large responses directed at the victim, the attacker's impact is magnified.
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Protocol-Based Attacks:
- Description: These attacks exploit weaknesses in network protocols, consuming server resources or network equipment capacity, leading to service disruptions.
- Examples:
- SYN Floods: The attacker sends a succession of SYN requests to initiate TCP connections but doesn't complete the handshake, leaving the server with numerous half-open connections and exhausting its resources.
- Ping of Death: Attackers send malformed or oversized ping packets to the target, causing buffer overflows and system crashes.
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Application Layer Attacks:
- Description: Targeting the top layer of the OSI model, these attacks focus on specific applications or services with the intent to exhaust their resources.
- Examples:
- HTTP Floods: Attackers send a high volume of HTTP requests to a web server, mimicking legitimate user behavior, making it challenging to distinguish from normal traffic.
- Slowloris: This technique involves sending partial HTTP requests to the server and keeping connections open as long as possible, eventually exhausting the server's connection pool and preventing it from serving legitimate requests.
How These Techniques Cause Disruptions:
- Resource Exhaustion: By overwhelming the target with excessive traffic or connection requests, DDoS attacks deplete critical resources such as bandwidth, memory, and processing power, leading to slowdowns or complete service outages.
- Service Downtime: Legitimate users are unable to access the service during an attack, resulting in potential revenue loss, reputational damage, and decreased user trust.
- Collateral Damage: Attacks can spill over to affect other services or networks connected to the primary target, amplifying the disruption.
Understanding these techniques is crucial for developing effective mitigation strategies to protect network services from DDoS attacks.
