Brazilian DDoS Mitigation Firm's Own Network Weaponized in Attack Campaign

Overview of the Incident

A Brazilian technology company that specializes in defending networks against distributed denial-of-service (DDoS) attacks has been implicated in a prolonged campaign of massive DDoS assaults targeting other network operators within Brazil. According to sources familiar with the investigation, the firm’s systems were compromised, and the malicious activity was orchestrated by a competitor seeking to damage its reputation. This article examines the details of the breach, the methods employed, and the broader implications for cybersecurity in the region.

Brazilian DDoS Mitigation Firm's Own Network Weaponized in Attack Campaign — Source: krebsonsecurity.com

Discovery of the Attack Infrastructure

For several years, security researchers have tracked a series of powerful DDoS attacks originating from Brazil and exclusively aimed at Brazilian Internet service providers (ISPs). The origin of these digital sieges remained unclear until recently, when a confidential source shared a suspicious file archive that had been exposed in an open directory online. The archive contained multiple Portuguese-language malicious scripts written in Python, along with the private SSH authentication keys belonging to the CEO of Huge Networks—a Brazilian ISP that primarily provides DDoS protection to other local network operators.

Background on Huge Networks

Founded in Miami, Florida, in 2014, Huge Networks operates primarily from Brazil. The company initially focused on protecting game servers from DDoS attacks and later evolved into an ISP-oriented DDoS mitigation provider. Despite its involvement in this incident, Huge Networks has no public record of abuse complaints and is not linked to any known DDoS-for-hire services.

How the Botnet Was Built

The exposed archive revealed that a threat actor based in Brazil maintained root-level access to Huge Networks’ infrastructure. Using this access, the attacker built a powerful DDoS botnet by continuously scanning the internet for vulnerable routers and unmanaged Domain Name System (DNS) servers that could be enlisted in attacks.

DNS Reflection and Amplification Techniques

DNS is crucial for translating domain names into IP addresses. Ideally, DNS servers only respond to queries from trusted domains. However, in so-called DNS reflection attacks, attackers exploit misconfigured DNS servers that accept queries from any source. By sending spoofed DNS queries that appear to originate from the target’s network, the attacker causes the DNS servers to respond to the target, flooding it with traffic.

To amplify the attack, criminals leverage an extension to the DNS protocol that allows large messages. For example, a query of less than 100 bytes can trigger a response up to 60–70 times larger. When combined with thousands of compromised devices querying many open DNS servers simultaneously, the amplification effect is devastating.

Implications for Brazilian ISPs

The attacks have severely disrupted multiple Brazilian ISPs over the past few years. The fact that the botnet was operated from within the infrastructure of a DDoS protection firm highlights the sophistication of the threat actors. The CEO of Huge Networks has stated that the malicious activity resulted from a security breach and was likely the work of a competitor aiming to tarnish the company’s public image.

Lessons for Network Security

This incident underscores the importance of securing internal administrative access, monitoring for unusual SSH key usage, and regularly auditing exposed directories. ISPs should also take measures to prevent DNS misconfiguration that enables reflection attacks. For more on securing DNS infrastructure, see our guide on DNS Security Best Practices.

DNS Security Best Practices

Restrict DNS server responses to queries from trusted networks only.
Disable recursion on authoritative DNS servers when not required.
Implement response rate limiting (RRL) to reduce amplification risks.
Regularly audit open directories and protect SSH keys with strong passwords.

Conclusion

The case of Huge Networks shows that even companies designed to combat DDoS attacks can become vectors for such threats. The combination of compromised credentials, open directories, and misconfigured DNS servers allowed a single actor to build a formidable attack platform. As Brazilian ISPs continue to face these onslaughts, the broader cybersecurity community must learn from this incident to prevent similar breaches in the future.

For ongoing updates on DDoS threats, visit our Threat Tracker.

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