Marketing content regularly espouses, “threat actors continuously evolve their methodologies.” They rarely provide the supporting evidence, making this phrase seem like nothing more than AI-generated fear.
The reality is that Vercara’s monthly Distributed Denial of Service (DDoS) reports provide security teams with the data necessary to track these changes. For example, the UltraDDoS Protect Monthly Distributed Denial-of-Service Analysis For July 2025 recorded the largest ever attack reaching 2.4 Terabytes per second (Tbps) in bandwidth and 533 million packets per second (Mpps) in packet rate. The UltraDDoS Protect Monthly Distributed Denial-of-Service Analysis For August 2025 observed an even larger DDoS attack that peaked at 3.7Tbps with over 336 Mpps.
These attacks exhibit a scale and complexity that reflect a broader trend with malicious actors appearing to have successfully reconstituted and expanded their DDoS infrastructures after the law enforcement takedown operations in late 2024 and early 2025. As these extreme-scale threats are a broader trend, Vercara’s reports now use the classification “tsunami” to categorize events exceeding 1Tbps.
As threat actors re-establish their DDoS operations, organizations should understand what web DDoS tsunami attacks are and how to mitigate the risks they create.
What Is a Web DDoS Tsunami Attack?
A Web DDoS tsunami attack is a sophisticated, high-volume attack designed to bypass traditional defenses and cause widespread damage. They represent a tactical shift in the threat landscape by targeting Layer 7, the application layer. Unlike network-layer attacks, tsunami attacks directly target applications with traffic that appears legitimate, like massive volumes of HTTPS requests. The approach exhausts server resources like CPU, memory, and application logic. Since the traffic appears legitimate, traditional security tools struggle to identify this rising internet tide of malicious traffic.
When trying to identify these attacks, security teams need to analyze multiple dimensions, including:
- Attack volume: The total bandwidth consumed during the flood, which signals whether the attack is overwhelming available network capacity.
- Attack duration: The length of time the high-volume surge persists, indicating whether it’s a brief burst or a sustained tsunami-style assault.
- Attack transactions: The number of packets or requests generated, helping distinguish a true volumetric tsunami from smaller floods or application-layer attacks.
How Is a Tsunami Attack Different from a Carpet-Bombing Attack?
Over the last year, attackers appear to have shifted their methodologies by increasingly leveraging tsunami attacks instead of carpet bombing style DDoS attacks. For example, Vercara’s Bi-Annual DDoS Analysis Report notes that carpet bombing attacks accounted for only 12.20% of all observed attacks, a 94.75% decrease from the same period in 2024. For organizations tracking carpet bombing attacks, understanding how they differ from tsunami attacks improves risk mitigation capabilities.
The key differences between these attack methodologies fall into three categories:
- Tactic: While carpet bombing spreads attack traffic across a wide range of IPs, subnets, or even entire networks, tsunami attacks direct a massive, single concentrated wave at a specific target, host, service, or application.
- Objectives: While carpeting bombing attacks flood multiple endpoints at once, tsunami attacks saturate the total bandwidth capacity or overwhelm specific mitigation points with sheer volume.
- Effect: While carpet bombing attacks are more difficult to detect because traffic per IP might look like “background noise,” tsunami attacks maximize impact with sudden, overwhelming traffic spikes across multiple vectors, like UDP floods, amplification, or TCP floods.
What Is the Impact of a Web DDoS Tsunami Attack?
A successful tsunami attack leads to widespread damage across operations. When the first wave hits, the direct impact can lead to service disruptions while security teams struggle to investigate and contain the threat.
Direct Operational Disruption and Service Outages
A tsunami attack seeks to render services unavailable. The sustained pressure from the attacks can create cascading failures across interconnected systems, turning a targeted assault on an application into a major event causing an organizational crisis.
Financial Repercussions and Reputational Damage
Beyond immediate business interruption, the track can have long-term financial repercussions, including:
- Costs of emergency mitigation, like hiring a forensics team.
- Overtime for IT staff.
- Potential regulatory fines related to failed security controls.
Additionally, a successful tsunami attack can damage customer trust, causing questions about data security and service reliability.
Strain on Internal Resources
A web DDoS tsunami attack places an immense burden on a Security Operations Center (SOC). Analysts may need to manually sift through millions of requests trying to identify the attack’s root cause. Meanwhile, the traffic’s sheer volume can lead to alert fatigue as logging and monitoring systems generate more notifications.
How Does a Tsunami Attack Work?
Tsunami attacks are dynamic and multifaceted. Rather than relying on a single vector, the attackers combine various methods seeking to overwhelm security teams. Tsunami attacks indicate a tactical shift as the attackers employ blended or multi-vector strategies. Many systems struggle to correlate events across the different layers, while signature-based protections often fail as the attacks have no repeating pattern to match.
Application Layer (Layer 7) Floods
Attackers launch HTTPS floods by sending high volumes of GET or POST requests that appear legitimate. They randomize HTTP headers, user agents, and source IPs to evade simple filtering rules and mimic real user behavior. Each request forces the server to
- Execute application code, forcing the server to repeatedly run resource-intensive logic, exhausting CPU and memory.
- Establish a database connection, overwhelming the database pool and leading to lockups or connection failures.
- Render a page, overloading threads, caching layers, and backend calls.
Network Layer (Layer 3/4) Floods
Although tsunami attacks focus on the application layer, attackers supplement those activities with traditional network-layer floods that include:
- SYN floods, half-open TCP handshakes that block legitimate connections before they reach the application.
- UDP floods, choking bandwidth and overwhelming ports with stateless traffic that leaves fewer resources for valid application requests.
- Fragmented UDP packets, consuming CPU and memory that would otherwise support application processing.
Best Practices for a Layered Approach to DDoS Protection
Using a layered approach to mitigate tsunami attack risks includes deploying multiple security controls across the digital infrastructure. Some best practices include:
- Deploy always-on network layer protection across key ingress points to detect and scrub traffic.
- Implement behavior-based algorithms to supplement signature-based protections for early anomalous traffic detections with sophisticated inspection and analysis of real-time traffic patterns.
- Apply rate-limiting as well as protocol, IP, and geographic filtering rules at the edge to limit traffic to any one source, protocol, or region.
- Maintain a globally distributed scrubbing infrastructure with multi-carrier connectivity so no single location or upstream provider becomes a bottleneck.
- Integrate hybrid deployment options and BGP or DNS redirection for traffic diversion to redirect large volumes of traffic away from vulnerable points.
- Use Web Application Firewalls (WAF) and Web Application and API Protection (WAAP) with both positive and negative security models to block application-layer abuse, like floods, malformed requests, and zero-day exploits.
- Keep low DNS TTLs and prepare DNS as well as routing redirections in advance to speed up traffic rerouting, minimizing downtime.
UltraDDoS: Layered Protection to Mitigate Web Tsunami DDoS Attack Risk
UltraDDoS Protect is the purpose-built defense against massive volume attacks, providing ultra-fast detection and mitigation on a global scale, UltraDDoS successfully protects against tsunami attacks, delivering a high-capacity network with flexible deployment options so organizations can implement sophisticated traffic scrubbing across multiple vectors.
To learn more about UltraDDoS Protect, contact us today for a demo.
