Assess the Damage
The first step after a DDoS attack is to determine what systems were impacted, how badly, and for how long. IT and security teams should immediately check logs and alerts to see which servers, networks, and applications were targeted. According to a guide by CISA, examining system performance reports can help quantify the impact and pinpoint where degradation occurred. This allows responders to ascertain the scope and severity of the attack (CISA).
A thorough damage assessment involves gathering data on key performance indicators like bandwidth usage, connection rate, CPU/memory utilization, and system uptime. Teams should document which services were disrupted or taken offline and the duration of downtime. According to security firm Netscout, it’s also important to estimate costs associated with lost revenue, recovery efforts, and reputational harm (Netscout). Having metrics on the impact can help justify investments into DDoS defenses.
Identify the Source
Work with your security team to pinpoint the originating IP addresses of the attack. Your network and security monitoring tools can help gather forensic evidence to identify the source IPs behind a DDoS assault. For example, products like Kentik offer DDoS detection capabilities through traffic flow monitoring. It’s also crucial to capture packet data during the attack, which can be analyzed after the incident is over.
Network flow records and packet captures can reveal the original sender’s IP address, despite IP spoofing efforts. Analyze the traffic to determine the attack vectors, tools, and patterns. Trace the IP addresses to identify the geographic location of the botnet controlling the DDoS. Look for related attacks from the same IP ranges. Pinpointing the originating sources is key to stopping an ongoing DDoS and preventing future attacks.
Mitigate Ongoing Attack
Once a DDoS attack is detected, it is crucial to quickly implement mitigation techniques to minimize disruption. Some key ways to mitigate an ongoing DDoS attack include:
- Implement filtering and rate limiting on routers and firewalls to block malicious traffic. This can help filter out the “bad” traffic while allowing legitimate users through (https://www.menandmice.com/blog/9-ways-to-mitigate-ddos-attacks).
- Use null routing or “black holing” to redirect DDoS traffic to nowhere, preventing it from reaching its target. This is an effective technique for absorbing large volume attacks (https://www.cyber.nj.gov/this-is-security/ddos-attack-types-and-mitigation-strategies).
- Leverage DDoS mitigation services offered by internet service providers, content delivery networks, or cloud providers. These services can quickly and efficiently scrub attack traffic before it reaches your infrastructure (https://aws.amazon.com/shield/ddos-attack-protection/).
The faster malicious traffic can be identified and filtered, the less impact there will be on legitimate users and business operations. A robust DDoS mitigation strategy is key to limiting damages.
Communicate with Stakeholders
It’s crucial to let customers, employees, and partners know about the DDoS attack in a timely manner. Send out notifications across your website, social media, email newsletters, etc. Explain what happened and how you are responding to the incident. Provide regular status updates as you work to mitigate the attack.
Be transparent in communicating the impact of the attack. Let people know if certain services are degraded or unavailable, along with an estimate of when functionality may be restored. Setting proper expectations can help ease concerns and frustration.
Designate a point person as the main contact for internal and external communications pertaining to the attack. Having a unified voice will help ensure messaging is clear, accurate, and consistent across channels.
Monitor social media for customer complaints or concerns stemming from the attack. Respond promptly with assistance and empathy. The way you communicate during an incident like a DDoS attack can have a lasting impact on your reputation and customer trust.
Improve Defenses
One of the most important things to do after a DDoS attack is to review and bolster your DDoS protections to prevent future attacks from being as effective. There are several key areas to focus on:
Review your bandwidth capacity and determine if you need to increase it to withstand larger attacks. Adding more bandwidth makes it harder for an attack to saturate your pipes and deny legitimate traffic [1].
Consider employing DDoS mitigation services or CDNs that can scrub incoming traffic before it reaches your infrastructure. Services like Cloudflare [2] and Akamai provide DDoS protection by filtering out malicious traffic.
Evaluate the effectiveness of current security tools and protections. Look at adding or upgrading solutions like firewalls and intrusion detection systems to better detect and halt DDoS traffic.
Implement rate limiting on application interfaces and other entry points. This can throttle traffic to help prevent resource exhaustion.
The goal is to have robust, layered DDoS defenses so that future attacks have minimal impact on infrastructure and services.
Conduct Post-Mortem
A critical step after a DDoS attack is to conduct a thorough post-mortem analysis to document how the attack unfolded and identify any vulnerabilities or gaps in defenses. As outlined in Ory Network’s Post-Mortem, the post-mortem should reconstruct the timeline of the attack, noting key events and their impacts. Detailed traffic and log analysis can shed light on the attack vectors, points of failure, and effectiveness of mitigation efforts.
The post-mortem should document the vulnerabilities that were exploited, such as insufficient bandwidth, unpatched devices and software, or inadequate edge protection. As Walletguard highlights, multi-level DDoS attacks may target both the application layer and network layer, so all vulnerabilities should be noted.
The post-mortem analysis provides the foundation to create an action plan for improving defenses and preventing future attacks. This may involve procuring additional bandwidth, implementing software patches, hardening infrastructure, revisiting incident response plans, and strengthening edge protection with services like Cloudflare. The key is turning insights from the attack into concrete steps to enhance resilience.
Implement Monitoring
Put improved monitoring and alerting in place to detect future attacks. According to the SolarWinds SEM DDoS detection and mitigation tool, implementing comprehensive monitoring with anomaly detection can help identify unusual traffic spikes or other indicators of a DDoS attack. This allows faster detection and response before significant damage occurs.
There are specialized monitoring tools that can analyze traffic patterns across networks and servers to identify potential DDoS activity. These tools can send alerts to quickly mobilize a response team. It’s also important to implement performance monitoring on critical systems to measure typical load levels. This establishes a baseline to more easily identify abnormal traffic associated with an attack.
Enable logging across all systems and aggregate logs into a central repository. Logs can provide forensic evidence to analyze attack patterns for future prevention. Make sure monitoring and alerting tools are configured correctly to notify the right individuals capable of responding swiftly to minimize downtime and disruption.
Harden Infrastructure
A key step in preventing future DDoS attacks is to harden the infrastructure against attack vectors. This involves eliminating single points of failure and improving capacity to handle spikes in traffic.
To eliminate single points of failure, use redundancy and load balancing across servers and data centers. For example, distribute traffic across multiple servers rather than routing all traffic to a single server. This ensures the infrastructure can withstand an attack on any one component.How To Prevent DDoS Attacks: 8 Best Practices
Improving capacity involves upgrading bandwidth, routers, load balancers, and other networking components to handle traffic spikes. Use stress testing to determine capacity limits. Implement bandwidth throttling and traffic shaping to manage bandwidth usage. Deploy extra capacity at locations prone to flooding attacks.How to Prevent DDoS Attacks: 5 Steps for DDoS Prevention
Revisit Incident Response
Updating DDoS response playbooks based on lessons learned from a DDoS attack is crucial for improving defenses against future incidents. The incident response team should hold a retrospective meeting to review what worked well and what areas need improvement in the response process.
Key items to examine include the effectiveness of detection mechanisms, the speed and coordination of the response, communication protocols, mitigation techniques, and impacted systems and services. The team should identify gaps that allowed the attack to occur or persist as well as any technical or procedural bottlenecks that slowed the response.
Based on this review, the incident response playbooks and procedures should be updated as needed. For example, thresholds for attack detection alerts may need adjustment, new mitigation strategies may be required, and responsibilities for various response tasks may need clarification.
Implementing recommendations from the post-mortem report will improve the efficiency and resilience of responses to future DDoS attacks. Periodically conducting response exercises and simulations can also validate the updated incident response capabilities.
Consider Legal Action
Consult with legal counsel about tracing the attack and prosecuting the perpetrators. DDoS attacks may violate computer crime laws and lead to civil liability or criminal charges, depending on the circumstances and jurisdiction. According to Can you sue someone for DDoS-ing you?, you can sue for damages if you can show the attack cost your business money. Tracing the attack often requires working with law enforcement or specialized cybersecurity firms. If the perpetrators are identified, charges like computer tampering, hacking, electronic vandalism or unauthorized access may apply, with penalties varying by state. For instance, according to Is DDoSing Illegal?, DDoS charges can potentially lead to multi-year prison sentences if intention to cause harm is proven. Consult qualified legal counsel to determine viable options based on the specific circumstances.
