A new Internet-of-Things 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 threat to organizations, and new research reveals Kimwolf is surprisingly prevalent in government and corporate networks.

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.

Our first story of 2026 revealed how a destructive new botnet called Kimwolf rapidly grew to infect 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 cybercrime services that appear to have benefitted from Kimwolf's spread.

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you thought you knew about the security of the internal network behind your Internet router probably is now dangerously out of date.

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 primary focus on entities that enabled complex and globally-dispersed cybercrime services.

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 efforts to restrict free speech and freedom of the press, have come at such a rapid clip that many readers probably aren’t even aware of them all.

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 visitors to sites that foist scams and malware.