Wireless jamming attacks are on the rise. Rice University researchers have shown how self-curving radio beams can make a jammer appear to be somewhere it isn't, potentially undermining some anti-jamming defenses. Jamming relies on flooding a wireless receiver with noise that denies service. Some modern receivers identify and block jamming attempts using direction-of-arrival (DoA) estimation technology that pinpoints the jammer's direction and directs an array null that blocks signals emanating in the jammer’s direction. Were a jammer to transmit a self-curving beam, however, it could fool DoA-based anti-jamming defenses by appearing to come from somewhere else entirely, and that's exactly what the Rice researchers demonstrated. Rice electrical and computer engineering professor Edward Knightly and doctoral student Caroline Spindel presented a paper [PDF] last month in which they demonstrated a curving-beam jamming attack that caused "catastrophic bit-error-rate degradation" while also "fool[ing] the receiver's DoA estimator," preventing conventional DoA-based defenses from stopping the interference. Knightly and Spindel have done prior research developing wireless technology that could bend beams around objects to increase signal strength - particularly useful for short-range millimeter wave signals - and found that the same technology could be used to deploy jammers that are far harder to locate. Spindel gave the perfect analogy in a recent Rice press release about the research for understanding how curved beams confuse DoA estimators by considering a soccer ball kick to the head. “Imagine being hit on the right side of your head by a soccer ball - you would naturally look to the right,” Spindel said. “If the ball actually curved through the air, like a David Beckham free kick, then it was kicked from somewhere else entirely.” Were Sir David to keep moving and kicking curveballs at your head you’d probably spot him eventually, but it might take a minute, and a few more smacks, to stop him. A signal jammer at radio-wave distances will probably be far harder to spot, and it won’t even have to move: Knightly and Spindel were able to create the illusion that the jammer was mobile by modulating the beam parameters from a stationary position, making it even more difficult to locate the jamming signal and negating the point of blindly searching for the best spot to point an array null. Conventional recovery methods used to block jamming completely failed in laboratory tests, Spindel said. “This is the first demonstration of a jammer that cannot be reliably localized and the first time self-curving wireless beams have been used as an attack,” Knightly added. The pair sees their research not just as a way to point out a serious threat to wireless signals - GPS jamming of aircraft is on the rise, for example - but also something that can inform the direction of future wireless technologies as we move toward the 6G era. Until then, however, there’s the potential for even more devastating jamming attacks to come. ®

The British government wants stronger protection for subsea internet cables following a surge in Russian activity near UK waters, but its latest proposals lean heavily on fines and prison sentences rather than direct defensive action. Plans - outlined in a speech by Baroness Liz Lloyd, Minister for Digital Economy ahead of a consultation - include tougher penalties for recklessly damaging undersea cables, operator security obligations and emergency powers allowing government to compel businesses to better protect their infrastructure. In April, the Royal Navy and Royal Air Force tracked Russian submarines on a covert reconnaissance near critical undersea infrastructure. According to reports, Russia deployed an Akula-class attack submarine as a decoy while two specialist vessels from Directorate of Deep Sea Research - known as Glavnoye Upravlenie Glubokovodnikh Issledovanii (GUGI) - surveyed the UK's cable routes. “Their mission was to survey our cables in peacetime, so they could more easily sabotage them in a conflict,” Lloyd said in a speech delivered at the Royal United Services Institute (RUSI). “They wanted this operation to be secret, but they failed." In light of this, the government is reviewing whether the UK’s security and resilience arrangements are strong enough, the Defence, Science and Technology Laboratory said. UK Parliament's Joint Committee on National Security Strategy (JCNSS) last year told the government it is "too timid" in its approach to protecting Britain’s cable connections, and must do a better job. Measures proposed include tightening the law so ship owners and operators that recklessly damage subsea internet cables face tougher penalties. Cable operators could be landed with extra obligations to ensure they take steps to prevent, detect and respond to security incidents in a consistent and timely manner. “The UK already has strong protections in place for our subsea cables, but in a more uncertain world we cannot stand still,” said Lloyd. "As hostile activity by Russia and others grows, protecting these cables matters more than ever for our economy, security and daily lives.” Some 64 cables connect Britain to the global internet, and when one breaks, repair vessels are typically on scene within eight days. Historically, most cable faults have stemmed from fishing activity or dragging anchors, not sabotage. The Royal Navy unveiled its Atlantic Bastion program last year to supplement its sub-hunting ships with a force of uncrewed, autonomous vessels. The aim is that enemy submarines in the North Atlantic have nowhere to hide. This is in its early stages, with £14 million committed so far for testing and development. The latest proposals will be outlined a white paper published later this year. Separately, the UK, US, and Australia announced this weekend that their AUKUS partnership will jointly develop sensor and weapons payloads for uncrewed underwater vehicles, which is another building block for protecting seabed infrastructure. ®

Cisco will make around five percent of staff redundant and has generously offered them free Cisco training for a year once they’re gone. CEO Chuck Robbins broke the news in a Wednesday blog post titled “Our Path Forward” that opens “Today we announced our Q3 FY26 earnings with record revenue of $15.8 billion, up 12 percent year over year, and double-digit top and bottom-line growth. The ELT [executive leadership team] and I could not be prouder of the growth you have all delivered for Cisco.” That growth included net income growing 35 percent to $3.4 billion. Yet Robbins’ pride was not sufficient for all Cisco staff to keep their jobs. The CEO said the layoffs are necessary because “The companies that will win in the AI era will be those with focus, urgency, and the discipline to continuously shift investment toward the areas where demand and long-term value creation are strongest.” For Cisco that means “reducing roles in some areas” and also “making clear, strategic investments – particularly in silicon, optics, security, and in our employees’ use of AI across the company.” On Thursday, US time, close to 4,000 unlucky Cisco staff will be shown the door. Robbins said Cisco will help its soon-to-be-former workers find their next gig, and that the company’s efforts to do so have a 75 percent success rate. “We are also committed to continued personalized learning and will provide one year of access to all Cisco U courses and certifications, covering AI, Security, Networking, and more,” he added. Cisco made two big rounds of layoffs in 2024, one of which ejected seven percent of staff and the other resulted in Cisco firing five percent of employees. The restructures appear not to have slowed the company down: Robbins said product orders in Q3 rose 35 percent year over year – a figure that encapsulates a 105 percent year-over-year surge in revenue from hyperscalers and more modest 18 percent growth from other buyers. Robbins said Cisco has already scored $5.3 billion of AI infrastructure sales this year, and forecast full-year sales of $9 billion – 4.5 times its haul from last year. More prosaic products, like Wi-Fi kit, also grew fast as sales rose 40 percent. The company hopes to keep that cash flowing by building wireless kit that uses less memory. “You’ll see products that’ll become orderable in Q4 that’ll actually require 50 percent less memory,” Robbins said, with the design work to make that possible an example of the “20-plus programs that we’ve put into place that are active to reduce the memory utilization across the portfolio.” Cisco’s doing that despite the rising price of memory and storage not putting a dent in its margins, an outcome that execs attributed to supply chain management efforts. Glasswing to lift security sales Later in the earnings call, Robbins revealed that Cisco is participating in Anthropic’s Project Glasswing and using the Mythos model to test its code. The CEO said another impact of Anthropic’s bug-finding AI will be to accelerate plans to replace security appliances once other vendor’s use of Mythos finds flaw that are hard to fix. “I actually think while there will be a security opportunity, there’s going to most likely be a lot of focus from our customers on modernizing their infrastructure so that they don’t have this risk from technology that just can’t be patched,” Robbins said. Robbins said Cisco may have won an order or two from customers who were already close to replacing old security kit “and Mythos pushed them over the edge.” But he said Cisco didn’t receive “any meaningful orders in Q3 as a result of Mythos, but that could change in the future as we continue to work with customers.” ®

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.

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