DDoS attacks are one of those cybersecurity threats that can bring down even well-prepared websites and services. Unlike other attacks that come from a single source, DDoS attacks use multiple compromised systems to overwhelm your servers with traffic, making them incredibly difficult to stop once they’re underway.

Here’s what you need to know about DDoS attacks and how to protect yourself against them.

What is a DDoS attack?

DDoS stands for Distributed Denial of Service. The goal is simple: flood your website or network with more traffic than it can handle, causing it to slow down or crash completely.

The “distributed” part is what makes these attacks particularly challenging. Instead of coming from one computer, the malicious traffic comes from hundreds or thousands of different sources – often compromised computers that the attackers have infected with malware.

When your server gets overwhelmed trying to respond to all these requests, legitimate visitors can’t access your site. For businesses that depend on their online presence, this can mean lost revenue, damaged reputation, and frustrated customers.

Common targets for DDoS attacks

While any website can be targeted, attackers typically focus on:

• E-commerce sites – Online stores are attractive targets because downtime directly impacts sales and revenue.
• Online gaming platforms – Gaming services often face attacks from competitors or disgruntled users.
• Financial services – Banks and payment processors are high-value targets that can cause widespread disruption.
• Government and institutional websites – These attacks are often politically motivated.
• Any business offering online services – SaaS platforms, hosting providers, and web applications are common targets.

How DDoS attacks evolved

The first recorded DDoS attack happened in 1996 against Panix, one of New York’s oldest Internet Service Providers. Attackers used a SYN flood technique that overwhelmed the company’s servers for days.

It took a coordinated effort from internet experts around the world about 36 hours to restore service. This early attack demonstrated both the potential impact of DDoS attacks and how difficult they can be to mitigate.

Since then, attacks have grown significantly in size and sophistication. Modern DDoS attacks can generate traffic measured in terabits per second – thousands of times larger than early attacks.

Recognizing a DDoS attack

DDoS attacks don’t always announce themselves clearly. Sometimes the first sign is simply that your website has stopped working or is running extremely slowly. Technical indicators include:

• 503 “Service Unavailable” errors – If these appear consistently across your site, your servers may be overwhelmed.
• Increased 404 errors – A sudden spike in 404 responses can indicate your server is struggling to handle requests properly.
• Unusual traffic patterns – Massive traffic spikes from unexpected sources or geographic regions.
• Network performance issues – Slow loading times, timeouts, and connection failures.

The challenge is that these symptoms can also indicate legitimate traffic spikes or server problems. Setting up monitoring and baseline metrics helps you distinguish between normal issues and potential attacks.

Notable Recent Attacks

Amazon Web Services (February 2020)

AWS experienced what was then the largest recorded DDoS attack, peaking at 2.3 terabits per second. The attack lasted three days and increased traffic to the targeted IP address by 56-70 times normal levels.

AWS’s Shield protection service managed to mitigate most of the impact, but some hosting customers still experienced revenue losses and service disruptions.

GitHub (February 2018)

GitHub faced a 1.35 terabits per second attack that lasted about 20 minutes. While shorter than the AWS attack, it demonstrated how quickly modern DDoS attacks can reach massive scale.

The attack used amplification techniques to multiply the attackers’ traffic, making relatively few attacking systems generate enormous amounts of malicious traffic.

DDoS Attack Trends

The frequency and scale of DDoS attacks continue to grow. Industry reports suggest several concerning trends:

• Attack frequency is increasing – Predictions indicate DDoS attacks could double to over 15 million annually by the mid-2020s.
• Attacks are getting larger – Multi-terabit attacks, once rare, are becoming more common as attackers gain access to more powerful botnets.
• Attack techniques are evolving – Attackers use increasingly sophisticated methods to bypass traditional defenses.
• Cost of cybercrime is rising – Global losses from all types of cybercrime, including DDoS attacks, continue to increase year over year.

Preventing and Mitigating DDoS Attacks

While you can’t prevent all DDoS attacks, you can significantly reduce their impact with proper preparation.

1. Implement Layered Security

Strong overall security practices make your infrastructure more resilient to attacks. This includes:

• Robust firewalls – Configure firewalls to filter out obviously malicious traffic before it reaches your servers.
• Intrusion prevention systems – Deploy systems that can identify and block attack patterns in real-time.
• Strong authentication – Secure all administrative access to prevent attackers from compromising your systems.
• Regular security updates – Keep all systems patched and updated to prevent compromise.

While these measures won’t stop a large DDoS attack by themselves, they reduce your overall attack surface and make you a less attractive target.

2. Build Redundant Infrastructure

Single points of failure make DDoS attacks more effective. Distribute your resources to improve resilience:

• Multiple servers – If attackers overwhelm one server, others can continue handling legitimate traffic.
• Geographic distribution – Hosting resources in different locations makes it harder for attackers to target your entire infrastructure.
• Load balancing – Distribute traffic across multiple servers to prevent any single system from becoming overwhelmed.
• Content delivery networks (CDNs) – CDNs can absorb and filter malicious traffic before it reaches your main servers.

3. Monitor for Warning Signs

Early detection gives you more options for responding to attacks:

• Traffic monitoring – Watch for unusual spikes in traffic volume or requests from specific sources.
• Performance metrics – Monitor response times, error rates, and server resource usage.
• Geographic patterns – Sudden traffic increases from unexpected regions can indicate an attack.
• Automated alerts – Set up alerts for abnormal traffic patterns so you can respond quickly.

4. Professional DDoS Protection Services

For many organizations, professional DDoS protection services provide better protection than in-house solutions. These services offer:

• Massive capacity – Protection services have the bandwidth and infrastructure to absorb large attacks.
• Specialized expertise – Security professionals who understand current attack methods and mitigation techniques.
• 24/7 monitoring – Continuous monitoring and rapid response when attacks are detected.
• Advanced filtering – Sophisticated systems that can distinguish between legitimate and malicious traffic.

Popular DDoS protection services include Cloudflare, AWS Shield, Akamai, and specialized security companies.

When Attacks Happen

If you suspect you’re under DDoS attack, act quickly:

• Contact your hosting provider – They may have tools and expertise to help mitigate the attack.
• Activate DDoS protection – If you have protection services, make sure they’re active and configured properly.
• Communicate with stakeholders – Let customers and partners know you’re aware of the issue and working to resolve it.
• Document the attack – Keep records for insurance claims, law enforcement, or future prevention efforts.

Conclusion

The truth is that DDoS attacks are becoming a routine part of operating online services. Rather than hoping you’ll never be targeted, it’s better to assume you will be and prepare accordingly.

Most successful DDoS defense combines good basic security practices with professional protection services. Small websites might get by with basic protections, but any business that depends on online availability should invest in proper DDoS protection before they need it.

The cost of prevention is almost always lower than the cost of dealing with a successful attack, especially when you factor in lost revenue, damaged reputation, and recovery time.