Distributed Denial-of-Service (DDoS) attacks continue to evolve, becoming more sophisticated and disruptive. One such emerging threat is the Hoaxcalls botnet, a rapidly expanding malware-driven campaign responsible for launching large-scale DDoS attacks against organizations worldwide. Since its initial discovery, Hoaxcalls has evolved in complexity, leveraging compromised devices to amplify attack traffic and overwhelm network infrastructures.
In this blog, we will explore the attack methodology of Hoaxcalls, its latest developments, and best practices for defending against this growing threat.
What is HoaxCalls?
Hoaxcalls is a botnet specifically designed to carry out high-volume DDoS attacks, exploiting vulnerable devices to create a powerful distributed attack network. Unlike traditional DDoS tools that rely solely on volumetric attacks, Hoaxcalls has demonstrated the ability to generate a variety of attack vectors, including TCP floods, UDP amplification attacks, and HTTP-based disruptions that target web applications and APIs.
This botnet primarily spreads by exploiting unpatched vulnerabilities in IoT devices, routers, and network infrastructure. Once a device is infected, it becomes part of the botnet, allowing attackers to issue remote commands to launch large-scale attacks against targeted organizations. The goal is to cause service disruptions, degrade network performance, or extort victims through DDoS-for-ransom campaigns.
The Evolution of HoaxCalls
Initially, Hoaxcalls operated as a relatively small-scale botnet, targeting unprotected systems with basic volumetric attacks. However, recent developments indicate a significant increase in its capabilities and reach:
- Expanded Attack Vectors: Modern variants of Hoaxcalls now incorporate multiple attack methods, including advanced reflection and amplification techniques, making mitigation more challenging.
- Wider Target Range: The botnet has been observed attacking critical infrastructure, cloud environments, and service providers, leading to prolonged service disruptions.
- Greater Automation and Resilience: Newer versions of Hoaxcalls feature self-propagation mechanisms, allowing it to continuously infect new devices and maintain its attack potential despite takedown efforts.
- Integration with Other Malware: Recent reports suggest that Hoaxcalls shares infrastructure with other botnets, increasing the risk of multi-vector cyberattacks that combine DDoS with credential theft, ransomware, or data exfiltration.
Why is HoaxCalls So Dangerous?
Several factors make Hoaxcalls a particularly effective and dangerous DDoS botnet:
- Massive Attack Scalability: The botnet can rapidly scale its attack power by leveraging thousands of compromised devices, resulting in high-bandwidth and high-packet-rate DDoS attacks.
- Exploitation of IoT Vulnerabilities: Hoaxcalls targets poorly secured or outdated IoT devices, allowing it to recruit new bots at an alarming rate.
- DDoS-for-Ransom Extortion: Attackers behind Hoaxcalls often demand ransom payments in exchange for halting their attacks, making it part of the growing ransom-driven DDoS (RDoS) threat landscape.
- Bypassing Traditional Defenses: Due to its diverse attack techniques, Hoaxcalls can evade standard rate-limiting or filtering mechanisms, requiring more advanced threat detection and mitigation strategies.
How to Defend Against Hoaxcalls
Organizations must take proactive steps to defend against Hoaxcalls and similar DDoS botnets:
- Deploy Advanced DDoS Protection: Utilize behavioral-based threat detection to identify and mitigate anomalous traffic patterns.
- Secure IoT and Network Devices: Regularly update firmware, disable unnecessary services, and apply strong authentication mechanisms to prevent botnet infections.
- Leverage Threat Intelligence: Stay updated on emerging botnet activity to anticipate attack trends and proactively strengthen defenses.
- Implement Scalable Mitigation Strategies: Ensure cloud-based DDoS scrubbing services and adaptive traffic filtering are in place to handle large-scale attacks.
For more detailed insights into the evolving HoaxCalls threat and actionable recommendations to safeguard your organization, we encourage you to view the full threat alert here.