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 …

A 24-year-old British national and senior member of the cybercrime group “ Scattered Spider ” has pleaded guilty to wire fraud conspiracy and aggravated identity theft. Tyler Robert Buchanan admitted his role in a series of text-message phishing attacks in the summer of 2022 that allowed the group to hack into …

Microsoft today pushed software updates to fix a staggering 167 security vulnerabilities in its Windows operating systems and related software, including a SharePoint Server zero-day and a publicly disclosed weakness in Windows Defender dubbed “ BlueHammer.” Separately, Google Chrome fixed its fourth zero-day of 2026, and an emergency update for …

Hackers linked to Russia’s military intelligence units are using known flaws in older Internet routers to mass harvest authentication tokens from Microsoft Office users, security experts warned today. The spying campaign allowed state-backed Russian hackers to quietly siphon authentication tokens from users on more than 18,000 networks …

An elusive hacker who went by the handle “ UNKN ” and ran the early Russian ransomware groups GandCrab and REvil now has a name and a face. Authorities in Germany say 31-year-old Russian Daniil Maksimovich Shchukin headed both cybercrime gangs and helped carry out at least 130 acts of computer …

A financially motivated data theft and extortion group is attempting to inject itself into the Iran war, unleashing a worm that spreads through poorly secured cloud services and wipes data on infected systems that use Iran’s time zone or have Farsi set as the default language. Experts say …

The U.S. Justice Department joined authorities in Canada and Germany in dismantling the online infrastructure behind four highly disruptive botnets that compromised more than three million Internet of Things (IoT) devices, such as routers and web cameras. The feds say the four botnets — named Aisuru, Kimwolf, JackSkid and …

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 …

Microsoft Corp. today pushed security updates to fix at least 77 vulnerabilities in its Windows operating systems and other software. There are no pressing “zero-day” flaws this month (compared to February’s five zero-day treat), but as usual some patches may deserve more rapid attention from organizations using Windows …

AI-based assistants or “agents” — autonomous programs that have access to the user’s computer, files, online services and can automate virtually any task — are growing in popularity with developers and IT workers. But as so many eyebrow-raising headlines over the past few weeks have shown, these powerful and assertive …

In early January 2026, KrebsOnSecurity revealed how a security researcher disclosed a vulnerability that was used to build Kimwolf, the world’s largest and most disruptive botnet. Since then, the person in control of Kimwolf — who goes by the handle “ Dort ” — has coordinated a barrage of distributed denial-of-service (DDoS …

Most phishing websites are little more than static copies of login pages for popular online destinations, and they are often quickly taken down by anti-abuse activists and security firms. But a stealthy new phishing-as-a-service offering lets customers sidestep both of these pitfalls: It uses cleverly disguised links to load …

For the past week, the massive “Internet of Things” (IoT) botnet known as Kimwolf has been disrupting The Invisible Internet Project (I2P), a decentralized, encrypted communications network designed to anonymize and secure online communications. I2P users started reporting disruptions in the network around the same time the Kimwolf botmasters …

Microsoft today released updates to fix more than 50 security holes in its Windows operating systems and other software, including patches for a whopping six “zero-day” vulnerabilities that attackers are already exploiting in the wild. Zero-day #1 this month is CVE-2026-21510, a security feature bypass vulnerability in Windows Shell …

A prolific data ransom gang that calls itself Scattered Lapsus ShinyHunters (SLSH) has a distinctive playbook when it seeks to extort payment from victim firms: Harassing, threatening and even swatting executives and their families, all while notifying journalists and regulators about the extent of the intrusion. Some victims reportedly …

The cybercriminals in control of Kimwolf — a disruptive botnet that has infected more than 2 million devices — recently shared a screenshot indicating they’d compromised the control panel for Badbox 2.0, a vast China-based botnet powered by malicious software that comes pre-installed on many Android TV streaming boxes …

A new Internet-of-Things (IoT) botnet called Kimwolf has spread to more than 2 million devices, forcing infected systems to participate in massive distributed denial-of-service (DDoS) attacks and to relay other malicious and abusive Internet traffic. Kimwolf’s ability to scan the local networks of compromised systems for other IoT …

Microsoft today issued patches to plug at least 113 security holes in its various Windows operating systems and supported software. Eight of the vulnerabilities earned Microsoft’s most-dire “critical” rating, and the company warns that attackers are already exploiting one of the bugs fixed today. January’s Microsoft zero-day …

Our first story of 2026 revealed how a destructive new botnet called Kimwolf has infected more than two million devices by mass-compromising a vast number of unofficial Android TV streaming boxes. Today, we’ll dig through digital clues left behind by the hackers, network operators and services that appear …

The story you are reading is a series of scoops nestled inside a far more urgent Internet-wide security advisory. The vulnerability at issue has been exploited for months already, and it’s time for a broader awareness of the threat. The short version is that everything you thought you …

KrebsOnSecurity.com celebrates its 16th anniversary today! A huge “thank you” to all of our readers — newcomers, long-timers and drive-by critics alike. Your engagement this past year here has been tremendous and truly a salve on a handful of dark days. Happily, comeuppance was a strong theme running through …

The Trump administration has pursued a staggering range of policy pivots this past year that threaten to weaken the nation’s ability and willingness to address a broad spectrum of technology challenges, from cybersecurity and privacy to countering disinformation, fraud and corruption. These shifts, along with the president’s …

Direct navigation — the act of visiting a website by manually typing a domain name in a web browser — has never been riskier: A new study finds the vast majority of “parked” domains — mostly expired or dormant domain names, or common misspellings of popular websites — are now configured to redirect …

Microsoft today pushed updates to fix at least 56 security flaws in its Windows operating systems and supported software. This final Patch Tuesday of 2025 tackles one zero-day bug that is already being exploited, as well as two publicly disclosed vulnerabilities. Despite releasing a lower-than-normal number of security updates …

A sprawling academic cheating network turbocharged by Google Ads that has generated nearly $25 million in revenue has curious ties to a Kremlin-connected oligarch whose Russian university builds drones for Russia’s war against Ukraine. The Nerdify homepage. The link between essay mills and Russian attack drones might seem …