A Record-Breaking Patch Tuesday for June 2026
Microsoft today released software updates to plug nearly 200 security holes across its Windows operating systems and supported software, a record number of fixes for the company’s monthly Patch Tuesday cycle. Nearly three dozen of those bugs earned Microsoft’s most dire “critical” rating, and exploit code for at least three of the weaknesses is now […]
Hackers Used Meta’s AI Support Bot to Seize Instagram Accounts
The Instagram accounts for the Obama White House and the Chief Master Sergeant of the U.S. Space Force were briefly defaced with pro-Iranian images and messages over the weekend, after instructions began circulating on Telegram showing how to trick Meta’s “AI support assistant” bot into resetting account passwords. A screenshot from a video released on […]
Netherlands Seizes 800 Servers, Arrests 2 for Aiding Cyberattacks
Authorities in the Netherlands have arrested the co-owners of two related Internet hosting companies for operating IT infrastructure used by Russia to carry out cyberattacks, influence operations and disinformation campaigns inside the European Union. The two men were the focus of a 2025 KrebsOnSecurity story about how their hosting companies had assumed control over the […]
Lawmakers Demand Answers as CISA Tries to Contain Data Leak
Lawmakers in both houses of Congress are demanding answers from the U.S. Cybersecurity & Infrastructure Security Agency (CISA) after KrebsOnSecurity reported this week that a CISA contractor intentionally published AWS GovCloud keys and a vast trove of other agency secrets on a public GitHub account. The inquiry comes as CISA is still struggling to contain […]
Alleged Kimwolf Botmaster ‘Dort’ Arrested, Charged in U.S. and Canada
Canadian authorities on Wednesday arrested a 23-year-old Ottawa man on suspicion of building and operating Kimwolf, a fast spreading Internet-of-Things botnet that enslaved millions of devices for use in a series of massive distributed denial-of-service (DDoS) attacks over the past six months. KrebsOnSecurity publicly named the suspect in February 2026 after the accused launched a […]
CISA Admin Leaked AWS GovCloud Keys on Github
Until this past weekend, a contractor for the Cybersecurity & Infrastructure Security Agency (CISA) maintained a public GitHub repository that exposed credentials to several highly privileged AWS GovCloud accounts and a large number of internal CISA systems. Security experts said the public archive included files detailing how CISA builds, tests and deploys software internally, and […]
Patch Tuesday, May 2026 Edition
Artificial intelligence platforms may be just as susceptible to social engineering as human beings, but they are proving remarkably good at finding security vulnerabilities in human-made computer code. That reality is on full display this month with some of the more widely-used software makers — including Apple, Google, Microsoft, Mozilla and Oracle — fixing near […]
Canvas Breach Disrupts Schools & Colleges Nationwide
An ongoing data extortion attack targeting the widely-used education technology platform Canvas disrupted classes and coursework at school districts and universities across the United States today, after a cybercrime group defaced the service’s login page with a ransom demand that threatened to leak data from 275 million students and faculty across nearly 9,000 educational institutions. […]
Anti-DDoS Firm Heaped Attacks on Brazilian ISPs
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 […]
‘Scattered Spider’ Member ‘Tylerb’ Pleads Guilty
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 at least a dozen major technology […]
Patch Tuesday, April 2026 Edition
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 Adobe Reader nixes an actively exploited […]
Russia Hacked Routers to Steal Microsoft Office Tokens
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 without deploying any malicious software or code. Microsoft […]
Germany Doxes “UNKN,” Head of RU Ransomware Gangs REvil, GandCrab
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 sabotage and extortion against victims across […]
‘CanisterWorm’ Springs Wiper Attack Targeting Iran
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 wiper campaign against Iran materialized this […]
Feds Disrupt IoT Botnets Behind Huge DDoS Attacks
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 Mossad — are responsible for a […]
Iran-Backed Hackers Claim Wiper Attack on Medtech Firm Stryker
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 […]
Microsoft Patch Tuesday, March 2026 Edition
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. Here are a few highlights from this […]
How AI Assistants are Moving the Security Goalposts
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 new tools are rapidly shifting […]
Who is the Kimwolf Botmaster “Dort”?
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), doxing and email flooding attacks […]
‘Starkiller’ Phishing Service Proxies Real Login Pages, MFA
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 the target brand’s real website, and […]
Kimwolf Botnet Swamps Anonymity Network I2P
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 began relying on it to evade […]
Patch Tuesday, February 2026 Edition
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 wherein a single click on a […]
Please Don’t Feed the Scattered Lapsus ShinyHunters
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 are paying — perhaps as much […]
Who Operates the Badbox 2.0 Botnet?
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. Both the FBI and Google say […]
Kimwolf Botnet Lurking in Corporate, Govt. Networks
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 devices to infect makes it a sobering […]
Patch Tuesday, January 2026 Edition
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 flaw — CVE-2026-20805 — is brought to us […]
Who Benefited from the Aisuru and Kimwolf Botnets?
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 to have benefitted from Kimwolf’s spread. On […]
The Kimwolf Botnet is Stalking Your Local Network
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 knew about the security of the internal […]
Happy 16th Birthday, KrebsOnSecurity.com!
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 our coverage in 2025, with a […]