Distributed Denial-of-Service (DDoS)
What is it and how can we defend against it.
A Distributed Denial-of-Service (DDoS) attack is a malicious attempt to disrupt the normal functioning of a targeted server, service, or network by overwhelming it with a flood of internet traffic. Unlike a regular Denial-of-Service (DoS) attack, which originates from a single source, a DDoS attack uses multiple compromised devices – often part of a botnet – to launch the attack simultaneously from many locations.
How a DDoS Attack Works:
- Infection: The attacker infects many devices (computers, IoT devices, etc.) with malware, turning them into “bots.”
- Control: These bots are controlled remotely by the attacker through a Command and Control (C&C) server.
- Attack Launch: All bots are instructed to send massive amounts of traffic or requests to the target at the same time.
- Overload: The target system becomes overwhelmed and can’t respond to legitimate users.
Common Types of DDoS Attacks:
- Volumetric attacks: Flood the network with high traffic (e.g., UDP floods, DNS amplification).
- Protocol attacks: Exploit weaknesses in network protocols (e.g., SYN floods).
- Application layer attacks: Target specific applications or services (e.g., HTTP floods).
Impact:
DDoS attacks can cause significant downtime, financial losses, and reputational damage. They are often used for extortion, political activism, or as a smokescreen for other cybercrimes.
How to Defend Against DDoS Attacks:
- Use firewalls and intrusion detection systems (IDS)
- Employ rate limiting and traffic filtering
- Use DDoS protection services (like Cloudflare, Akamai, or AWS Shield)
- Monitor network traffic for unusual patterns
- Have a response plan in place