A Brazilian tech firm that specializes in protecting networks from distributed denial-of-service (DDoS) attacks has been enabling a botnet responsible for an extended campaign of massive DDoS attacks against other network operators in Brazil, KrebsOnSecurity has learned. The firm’s chief executive says the malicious activity resulted from a security breach and was likely the work of a competitor trying to tarnish his company’s public image.

For the past several years, security experts have tracked a series of massive DDoS attacks originating from Brazil and solely targeting Brazilian ISPs. Until recently, it was less than clear who or what was behind these digital sieges. That changed earlier this month when a trusted source who asked to remain anonymous shared a curious file archive that was exposed in an open directory online.

The exposed archive contained several Portuguese-language malicious programs written in Python. It also included the private SSH authentication keys belonging to the CEO of Huge Networks, a Brazilian ISP that primarily offers DDoS protection to other Brazilian network operators.

Founded in Miami, Fla. in 2014, Huge Networks’s operations are centered in Brazil. The company originated from protecting game servers against DDoS attacks and evolved into an ISP-focused DDoS mitigation provider. It does not appear in any public abuse complaints and is not associated with any known DDoS-for-hire services.

Nevertheless, the exposed archive shows that a Brazil-based threat actor maintained root access to Huge Networks infrastructure and built a powerful DDoS botnet by routinely mass-scanning the Internet for insecure Internet routers and unmanaged domain name system (DNS) servers on the Web that could be enlisted in attacks.

DNS is what allows Internet users to reach websites by typing familiar domain names instead of the associated IP addresses. Ideally, DNS servers only provide answers to machines within a trusted domain. But so-called “DNS reflection” attacks rely on DNS servers that are (mis)configured to accept queries from anywhere on the Web. Attackers can send spoofed DNS queries to these servers so that the request appears to come from the target’s network. That way, when the DNS servers respond, they reply to the spoofed (targeted) address.

By taking advantage of an extension to the DNS protocol that enables large DNS messages, botmasters can dramatically boost the size and impact of a reflection attack — crafting DNS queries so that the responses are much bigger than the requests. For example, an attacker could compose a DNS request of less than 100 bytes, prompting a response that is 60-70 times as large. This amplification effect is especially pronounced when the perpetrators can query many DNS servers with these spoofed requests from tens of thousands of compromised devices simultaneously.

The exposed file archive includes a command-line history showing exactly how this attacker built and maintained a powerful botnet by scouring the Internet for TP-Link Archer AX21 routers. Specifically, the botnet seeks out TP-Link devices that remain vulnerable to CVE-2023-1389, an unauthenticated command injection vulnerability that was patched back in April 2023.

Malicious domains in the exposed Python attack scripts included DNS lookups for hikylover[.]st, and c.loyaltyservices[.]lol, both domains that have been flagged in the past year as control servers for an Internet of Things (IoT) botnet powered by a Mirai malware variant.

The leaked archive shows the botmaster coordinated their scanning from a Digital Ocean server that has been flagged for abusive activity hundreds of times in the past year. The Python scripts invoke multiple Internet addresses assigned to Huge Networks that were used to identify targets and execute DDoS campaigns. The attacks were strictly limited to Brazilian IP address ranges, and the scripts show that each selected IP address prefix was attacked for 10-60 seconds with four parallel processes per host before the botnet moved on to the next target.

The archive also shows these malicious Python scripts relied on private SSH keys belonging to Huge Networks’s CEO, Erick Nascimento. Reached for comment about the files, Mr. Nascimento said he did not write the attack programs and that he didn’t realize the extent of the DDoS campaigns until contacted by KrebsOnSecurity.

“We received and notified many Tier 1 upstreams regarding very very large DDoS attacks against small ISPs,” Nascimento said. “We didn’t dig deep enough at the time, and what you sent makes that clear.”

Nascimento said the unauthorized activity is likely related to a digital intrusion first detected in January 2026 that compromised two of the company’s development servers, as well as his personal SSH keys. But he said there’s no evidence those keys were used after January.

“We notified the team in writing the same day, wiped the boxes, and rotated keys,” Nascimento said, sharing a screenshot of a January 11 notification from Digital Ocean. “All documented internally.”

Mr. Nascimento said Huge Networks has since engaged a third-party network forensics firm to investigate further.

“Our working assessment so far is that this all started with a single internal compromise — one pivot point that gave the attacker downstream access to some resources, including a legacy personal droplet of mine,” he wrote.

“The compromise happened through a bastion/jump server that several people had access to,” Nascimento continued. “Digital Ocean flagged the droplet on January 11 — compromised due to a leaked SSH key, in their wording — I was traveling at the time and addressed it on return. That droplet was deprecated and destroyed, and it was never part of Huge Networks infrastructure.”

The malicious software that powers the botnet of TP-Link devices used in the DDoS attacks on Brazilian ISPs is based on Mirai, a malware strain that made its public debut in September 2016 by launching a then record-smashing DDoS attack that kept this website offline for four days. In January 2017, KrebsOnSecurity identified the Mirai authors as the co-owners of a DDoS mitigation firm that was using the botnet to attack gaming servers and scare up new clients.

In May 2025, KrebsOnSecurity was hit by another Mirai-based DDoS that Google called the largest attack it had ever mitigated. That report implicated a 20-something Brazilian man who was running a DDoS mitigation company as well as several DDoS-for-hire services that have since been seized by the FBI.

Nascimento flatly denied being involved in DDoS attacks against Brazilian operators to generate business for his company’s services.

“We don’t run DDoS attacks against Brazilian operators to sell protection,” Nascimento wrote in response to questions. “Our sales model is mostly inbound and through channel integrator, distributors, partners — not active prospecting based on market incidents. The targets in the scripts you received are small regional providers, the vast majority of which are neither in our customer base nor in our commercial pipeline — a fact verifiable through public sources like QRator.”

Nascimento maintains he has “strong evidence stored on the blockchain” that this was all done by a competitor. As for who that competitor might be, the CEO wouldn’t say.

“I would love to share this with you, but it could not be published as it would lose the surprise factor against my dishonest competitor,” he explained. “Coincidentally or not, your contact happened a week before an important event – ​​one that this competitor has NEVER participated in (and it’s a traditional event in the sector). And this year, they will be participating. Strange, isn’t it?”

Strange indeed.

A hacktivist group with links to Iran’s intelligence agencies is claiming responsibility for a data-wiping attack against Stryker, a global medical technology company based in Michigan. News reports out of Ireland, Stryker’s largest hub outside of the United States, said the company sent home more than 5,000 workers there today. Meanwhile, a voicemail message at Stryker’s main U.S. headquarters says the company is currently experiencing a building emergency.

Based in Kalamazoo, Michigan, Stryker [NYSE:SYK] is a medical and surgical equipment maker that reported $25 billion in global sales last year. In a lengthy statement posted to Telegram, a hacktivist group known as Handala (a.k.a. Handala Hack Team) claimed that Stryker’s offices in 79 countries have been forced to shut down after the group erased data from more than 200,000 systems, servers and mobile devices.

“All the acquired data is now in the hands of the free people of the world, ready to be used for the true advancement of humanity and the exposure of injustice and corruption,” a portion of the Handala statement reads.

The group said the wiper attack was in retaliation for a Feb. 28 missile strike that hit an Iranian school and killed at least 175 people, most of them children. The New York Times reports today that an ongoing military investigation has determined the United States is responsible for the deadly Tomahawk missile strike.

Handala was one of several hacker groups recently profiled by Palo Alto Networks, which links it to Iran’s Ministry of Intelligence and Security (MOIS). Palo Alto says Handala surfaced in late 2023 and is assessed as one of several online personas maintained by Void Manticore, a MOIS-affiliated actor.

Stryker’s website says the company has 56,000 employees in 61 countries. A phone call placed Wednesday morning to the media line at Stryker’s Michigan headquarters sent this author to a voicemail message that stated, “We are currently experiencing a building emergency. Please try your call again later.”

A report Wednesday morning from the Irish Examiner said Stryker staff are now communicating via WhatsApp for any updates on when they can return to work. The story quoted an unnamed employee saying anything connected to the network is down, and that “anyone with Microsoft Outlook on their personal phones had their devices wiped.”

“Multiple sources have said that systems in the Cork headquarters have been ‘shut down’ and that Stryker devices held by employees have been wiped out,” the Examiner reported. “The login pages coming up on these devices have been defaced with the Handala logo.”

Wiper attacks usually involve malicious software designed to overwrite any existing data on infected devices. But a trusted source with knowledge of the attack who spoke on condition of anonymity told KrebsOnSecurity the perpetrators in this case appear to have used a Microsoft service called Microsoft Intune to issue a ‘remote wipe’ command against all connected devices.

Intune is a cloud-based solution built for IT teams to enforce security and data compliance policies, and it provides a single, web-based administrative console to monitor and control devices regardless of location. The Intune connection is supported by this Reddit discussion on the Stryker outage, where several users who claimed to be Stryker employees said they were told to uninstall Intune urgently.

Palo Alto says Handala’s hack-and-leak activity is primarily focused on Israel, with occasional targeting outside that scope when it serves a specific agenda. The security firm said Handala also has taken credit for recent attacks against fuel systems in Jordan and an Israeli energy exploration company.

“Recent observed activities are opportunistic and ‘quick and dirty,’ with a noticeable focus on supply-chain footholds (e.g., IT/service providers) to reach downstream victims, followed by ‘proof’ posts to amplify credibility and intimidate targets,” Palo Alto researchers wrote.

The Handala manifesto posted to Telegram referred to Stryker as a “Zionist-rooted corporation,” which may be a reference to the company’s 2019 acquisition of the Israeli company OrthoSpace.

Stryker is a major supplier of medical devices, and the ongoing attack is already affecting healthcare providers. One healthcare professional at a major university medical system in the United States told KrebsOnSecurity they are currently unable to order surgical supplies that they normally source through Stryker.

“This is a real-world supply chain attack,” the expert said, who asked to remain anonymous because they were not authorized to speak to the press. “Pretty much every hospital in the U.S. that performs surgeries uses their supplies.”

John Riggi, national advisor for the American Hospital Association (AHA), said the AHA is not aware of any supply-chain disruptions as of yet.

“We are aware of reports of the cyber attack against Stryker and are actively exchanging information with the hospital field and the federal government to understand the nature of the threat and assess any impact to hospital operations,” Riggi said in an email. “As of this time, we are not aware of any direct impacts or disruptions to U.S. hospitals as a result of this attack. That may change as hospitals evaluate services, technology and supply chain related to Stryker and if the duration of the attack extends.”

According to a March 11 memo from the state of Maryland’s Institute for Emergency Medical Services Systems, Stryker indicated that some of their computer systems have been impacted by a “global network disruption.” The memo indicates that in response to the attack, a number of hospitals have opted to disconnect from Stryker’s various online services, including LifeNet, which allows paramedics to transmit EKGs to emergency physicians so that heart attack patients can expedite their treatment when they arrive at the hospital.

“As a precaution, some hospitals have temporarily suspended their connection to Stryker systems, including LIFENET, while others have maintained the connection,” wrote Timothy Chizmar, the state’s EMS medical director. “The Maryland Medical Protocols for EMS requires ECG transmission for patients with acute coronary syndrome (or STEMI). However, if you are unable to transmit a 12 Lead ECG to a receiving hospital, you should initiate radio consultation and describe the findings on the ECG.”

This is a developing story. Updates will be noted with a timestamp.

Update, 2:54 p.m. ET: Added comment from Riggi and perspectives on this attack’s potential to turn into a supply-chain problem for the healthcare system.

Update, Mar. 12, 7:59 a.m. ET: Added information about the outage affecting Stryker’s online services.

Koi has developed an endpoint security solution that Palo Alto will use to enhance its products.

The post Palo Alto Networks to Acquire Koi in Reported $400 Million Transaction appeared first on SecurityWeek.

Why AI's Biggest Risk Isn't Technical

This article is based on a conversation with Nikesh Arora on the 100th episode of the Threat Vector podcast.

"Most technologists think about technology, not about cybersecurity," Nikesh Arora says. "Cybersecurity is kind of like insurance. Let's go make great things happen, and let's make sure on the way we purchase insurance."

Coming from the CEO of the world's largest cybersecurity company, it's the quiet part said out loud, and it explains why AI deployment is racing ahead while security scrambles to keep up.

Earlier this year, Arora spoke with a CIO entirely focused on AI deployment challenges: building viable products, training models, measuring customer impact. Security never came up once. "If you're still going through the motion, trying to understand, ‘Can I actually make this thing work?’ You're not worried about security," Arora notes. The logic is brutal but consistent: Why secure something that might not even function?

In the Threat Vector podcast’s 100th episode milestone, Arora speaks with host David Moulton:

• Why the gap between innovation and security keeps widening.
• How to read inflection points before they're obvious.
• What separates organizations that prepare from those that scramble.

The Gap That Keeps Growing

The disconnect isn't new. It's the same psychology that makes airport security feel like overhead – necessary friction that slows down what should be seamless. But with AI, the gap is widening at an unprecedented pace.

Consider the infrastructure buildup happening right now. Nvidia has become a $4 trillion company selling chips that can't stay in stock. Hundreds of billions of dollars are flowing into AI-computer infrastructure. Cloud providers are buying out entire methane gas companies to power their data centers.

Yet organizations are treating AI security as something to bolt on later. That same CIO told Arora: "We worked on some stuff ourselves, and we're just jerry-rigging some things to make sure this happens securely."

Arora's response:

Jerry rig, production, and security don't work together as three terms.

Reading Signals Before They're Obvious

Arora has watched enough technology cycles to recognize the pattern. "You start seeing signs early, and then you look around, you don't see enough impact. You say, okay, maybe this is going to be just a passing shower. But you don't realize that over time this thing's getting more and more momentum."

The signs around AI are adding up:

• Individual behavior has shifted.
  Arora went from never talking to ChatGPT or Gemini to conducting 10-15 conversations daily. During a recent Tokyo trip, he used Gemini as his primary navigation tool, asking it to rank sumo wrestling shows for his kids rather than "trying to go read 14 websites and figure out what makes sense."
• The spend is massive and accelerating.
  Not just chips, entire energy infrastructures are being rebuilt to support AI compute needs.
• Consumer and enterprise adoption are both surging.
  From coding assistants to business analysis, use cases are expanding faster than security models can adapt.

"This thing's going to change our life fundamentally," Arora tells Moulton. "We're not seeing it at scale in our customers just yet. That doesn't mean we can sit back and wait."

Arora understands the risks involved in being late to new technology.

You have to not just anticipate where the trend is going. You have to prepare your organization and the resources to get there. Otherwise, the risk is that Silicon Valley will go fund those people who are thinking purely about the new world... and one of them's going to hit. Then you'll be two years behind with no organization, no resources deployed against it.

The Bets That Paid Off

When Arora joined Palo Alto Networks seven and a half years ago, he wrote two words on a piece of paper: cloud and AI. The company was a firewall business. Those two inflection points would require fundamental transformation, and, just as with AI now, being late was not an option.

If you don't get the network transformation right, 80% of our business will falter.

That insight drove a strategic bet on moving from point products to platform thinking, consolidating security tools rather than adding to the sprawl.

The platform approach wasn't about vendor consolidation for its own sake. It was about correlation. Unit 42® data shows that 70% of incidents now span three or more attack surfaces. When attacks move across endpoints, networks, cloud services and applications simultaneously, fragmented security creates gaps that attackers exploit ruthlessly.

Today we have coverage for 80 plus percent of the industry, which means our customers can come talk to us about a myriad of problems, and we can actually cross-correlate across all the different things we do.

With AI deployments touching every part of the technology stack, that cross-correlation becomes essential. Data flows between training environments and production systems. Models access APIs across cloud and on premises infrastructure. Applications consume AI services from multiple providers. Security that can't see and correlate across that entire landscape will miss the threats that matter most.

First Principles Over Tradition

What drives Arora's ability to spot inflection points isn't just pattern recognition, it's his refusal to accept how things have always been done.

His pet peeve: "Somebody said, well, this is how we've traditionally done it." The response reveals his approach: "You use the word traditional. I use the historical context saying, yeah, sure, they used to dig fields with picks and shovels, and now they use tractors."

This thinking drove Palo Alto Networks to reimagine SOC performance. The industry accepted four days as the normal time to detect and remediate security incidents. Arora called that unacceptable. "We need to get it to be real time."

The result was a fundamentally different architecture that analyzes data as it arrives rather than waiting for problems to appear, enabling 1-minute detection and response instead of four days.

Traditionally, SOCs would analyze the problem when the problem appeared. We said forget it. We're going to analyze everything to see if there's a problem. That architecture fundamentally transformed what we do compared to everybody else in the market.

The same first-principles approach needs to apply to AI security. Organizations can't simply extend existing security models and hope they work.

What Comes Next

With ransomware attacks now completing in as little as 25 minutes (100 times faster than just three years ago, according to Unit 42 research) reactive security simply can't keep pace. Organizations need security that thinks and responds at machine speed, built into AI deployments from day one.

"AI has become the biggest inflection point in current technology," Arora observes. Organizations are too busy deploying to worry about security. That's human nature. But it's also the moment when security teams need to stay in lockstep.

The question isn't whether to secure AI, it's whether security will be designed in or bolted on. The former takes strategic thinking now. The latter takes crisis management later.

Our job at Palo Alto and our industry is to make sure as they go build these experimental ideas into real production capability that we're staying in lockstep with them and saying, ‘Oh, by the way, here's something that can secure what you just built in a way that is not gonna get you into trouble.’

Listen to the full conversation between Nikesh Arora and David Moulton, senior director of thought leadership for Cortex^® and Unit 42, on the 100th episode of Threat Vector.

The post When Security Becomes an Afterthought appeared first on Palo Alto Networks Blog.

John talked about how we’d attack, here’s how you can defend against those attacks. Grab the slides here: https://blackhillsinformationsecurity.shootproof.com/gallery/6843799/

The post PODCAST: Attack Tactics Part 2 appeared first on Black Hills Information Security, Inc..

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