The Bizarre Case of a DDoS Protector Turned Attacker: Q&A on the Brazilian ISP Botnet Saga

For years, Brazilian internet service providers (ISPs) have been battered by relentless distributed denial-of-service (DDoS) attacks, with the source remaining a mystery. A recent explosive discovery has turned the narrative upside down: the attacks may have been orchestrated using the infrastructure of a company that claims to protect against them—Huge Networks, a Brazilian DDoS mitigation firm. This Q&A dives into the investigation, the methods used, and the fallout, revealing a tale of security breaches, fierce competition, and unintended consequences.

1. What triggered the investigation into the DDoS attacks on Brazilian ISPs?

For several years, security researchers tracked a wave of massive DDoS attacks originating from Brazil and targeting only Brazilian ISPs. The perpetrators and their motives were a black hole—until a confidential source shared a startling find: an exposed online directory containing a trove of malicious Portuguese-language Python scripts, along with the private SSH authentication keys of the CEO of Huge Networks. Huge Networks is a Miami-founded, Brazil-centered firm that specializes in protecting networks from DDoS attacks. The archive essentially tied the botnet activity directly to the CEO's credentials, suggesting that either the company was compromised or complicit. This discovery illuminated a dark twist: the very company built to shield networks may have been used as a weapon.

2. How did the attackers build and operate the botnet using Huge Networks' infrastructure?

According to the exposed archive, a Brazil-based threat actor maintained root access to Huge Networks' systems and systematically constructed a powerful botnet. The method was ruthless: mass-scanning the internet for insecure routers and poorly configured domain name system (DNS) servers. Once identified, these devices were enlisted to amplify attacks. The archive also contained SSH keys that allowed the attacker to remain hidden within Huge Networks' own network. By hijacking the company's infrastructure, the botmaster launched a campaign of DNS reflection and amplification attacks against other Brazilian ISPs, turning Huge Networks’ own capabilities against the industry it was supposed to protect.

3. What exactly is a DNS reflection attack, and why is it so devastating?

A DNS reflection attack exploits DNS servers that are misconfigured to respond to queries from any source. An attacker sends a small DNS request (e.g., less than 100 bytes) with a spoofed IP address—the target's IP. The DNS server then sends a larger response to that spoofed address, causing the target to receive traffic they never requested. The damage multiplies when combined with DNS amplification: by using the EDNS0 extension, attackers can craft queries that trigger responses 60–70 times larger than the request. For example, a 100-byte request can balloon into a 7,000-byte response. When thousands of compromised devices (the botnet) simultaneously query many such open DNS servers, the target gets flooded with massive traffic, overwhelming their network. Learn more about how the botnet amplified its power.

4. How did the botnet amplify its attacks beyond standard DNS reflection?

The botnet leveraged not only open DNS servers but also a vast army of compromised home routers (like the TP-Link Archer AX21) and unmanaged DNS servers. By controlling tens of thousands of these devices, the attacker could orchestrate synchronized, spoofed queries to many misconfigured DNS resolvers simultaneously. The amplification factor was enormous: each query generated a response many times larger, directed at the victim's IP. The botnet also rotated its attack vectors and used Portuguese-language command-and-control scripts, likely to evade detection. The combination of high-volume distributed sources and massive amplification made these attacks some of the largest ever seen in Brazil, crippling ISP networks for hours or days at a time.

5. How did Huge Networks' CEO respond to these revelations?

The CEO of Huge Networks, who asked to remain anonymous in the original report, claimed the malicious activity stemmed from a security breach within his own company. He suggested that a competitor hacked into Huge Networks' systems to tarnish its reputation, using the company's own infrastructure to launch attacks against other ISPs. While he acknowledged the archive contained his SSH keys, he insisted that the keys were stolen, not voluntarily shared. The CEO noted that Huge Networks has no history of public abuse complaints or involvement in DDoS-for-hire services. However, the revelation has cast a shadow over the firm's integrity, especially since it benefits directly from the chaos: when ISPs are under attack, they often turn to DDoS mitigation providers like Huge Networks.

6. What are the broader implications for the security industry and Brazilian ISPs?

This case underscores a critical vulnerability: even companies built to defend against DDoS attacks can be turned into offensive weapons if their infrastructure is compromised. For Brazilian ISPs, the attacks have caused significant financial and reputational damage. The incident also highlights the prevalence of open DNS servers and poorly secured routers in Brazil—a low-hanging fruit for botnet builders. ISPs are now being forced to reevaluate their trust in third-party mitigation services and invest in better internal scanning. Additionally, the legal and competitive tensions in the Brazilian ISP market may escalate, as accusations of sabotage fly between firms. The episode serves as a stark reminder that in the world of cybersecurity, defenders must constantly guard their own perimeters, or risk becoming the very threat they claim to fight.