Microsoft today released updates to fix at least 137 security vulnerabilities in its Windows operating systems and supported software. None of the weaknesses addressed this month are known to be actively exploited, but 14 of the flaws earned Microsoft's most-dire "critical" rating, meaning they could be exploited to seize control over vulnerable Windows PCs with little or no help from users.

In May 2025, the U.S. government sanctioned a Chinese national for operating a cloud provider linked to the majority of virtual currency investment scam websites reported to the FBI. But more than a month later, the accused continues to openly operate accounts at a slew of American tech companies, including Facebook, Github, LinkedIn, PayPal and Twitter/X.

Agents with the Federal Bureau of Investigation (FBI) briefed Capitol Hill staff recently on hardening the security of their mobile devices, after a contacts list stolen from the personal phone of the White House Chief of Staff Susie Wiles was reportedly used to fuel a series of text messages and phone calls impersonating her to U.S. lawmakers. But in a letter this week to the FBI, one of the Senate's most tech-savvy lawmakers says the feds aren't doing enough to recommend more appropriate security protections that are already built into most consumer mobile devices.

Late last year, security researchers made a startling discovery: Kremlin-backed disinformation campaigns were bypassing moderation on social media platforms by leveraging the same malicious advertising technology that powers a sprawling ecosystem of online hucksters and website hackers. A new report on the fallout from that investigation finds this dark ad tech industry is far more resilient and incestuous than previously known.

Microsoft today released security updates to fix at least 67 vulnerabilities in its Windows operating systems and software. Redmond warns that one of the flaws is already under active attack, and that software blueprints showing how to exploit a pervasive Windows bug patched this month are now public. 

Ukraine has seen nearly one-fifth of its Internet space come under Russian control or sold to Internet address brokers since February 2022, a new study finds. The analysis indicates large chunks of Ukrainian Internet address space are now in the hands of proxy and anonymity services nested at some of America's largest Internet service providers (ISPs).

The U.S. government today imposed economic sanctions on Funnull Technology Inc., a Philippines-based company that provides computer infrastructure for hundreds of thousands of websites involved in virtual currency investment scams, commonly known as “pig butchering." In January 2025, KrebsOnSecurity detailed how Funnull was being used as a content delivery network that catered to cybercriminals seeking to route their traffic through U.S.-based cloud providers.

Authorities in Pakistan have arrested 21 individuals accused of operating "Heartsender," a once popular spam and malware dissemination service that operated for more than a decade. The main clientele for HeartSender were organized crime groups that tried to trick victim companies into making payments to a third party, and its alleged proprietors were publicly identified by KrebsOnSecurity in 2021 after they inadvertently infected their computers with malware.

The U.S. government today unsealed criminal charges against 16 individuals accused of operating and selling DanaBot, a prolific strain of information-stealing malware that has been sold on Russian cybercrime forums since 2018. The FBI says a newer version of DanaBot was used for espionage, and that many of the defendants exposed their real-life identities after accidentally infecting their own systems with the malware.

KrebsOnSecurity last week was hit by a near record distributed denial-of-service (DDoS) attack that clocked in at more than 6.3 terabits of data per second (a terabit is one trillion bits of data). The brief attack appears to have been a test run for a massive new Internet of Things (IoT) botnet capable of launching crippling digital assaults that few web destinations can withstand. Read on for more about the botnet, the attack, and the apparent creator of this global menace.

In what experts are calling a novel legal outcome, the 22-year-old former administrator of the cybercrime community Breachforums will forfeit nearly $700,000 to settle a civil lawsuit from a health insurance company whose customer data was posted for sale on the forum in 2023. Conor Brian Fitzpatrick, a.k.a. "Pompompurin," is slated for resentencing next month after pleading guilty to access device fraud and possession of child sexual abuse material (CSAM).

Microsoft on Tuesday released software updates to fix at least 70 vulnerabilities in Windows and related products, including five zero-day flaws that are already seeing active exploitation. Adding to the sense of urgency with this month's patch batch from Redmond are fixes for two other weaknesses that now have public proof-of-concept exploits available.

A Texas firm recently charged with conspiring to distribute synthetic opioids in the United States is at the center of a vast network of companies in the U.S. and Pakistan whose employees are accused of using online ads to scam westerners seeking help with trademarks, book writing, mobile app development and logo designs, a new investigation reveals.

A employee at Elon Musk's artificial intelligence company xAI leaked a private key on GitHub that for the past two months could have allowed anyone to query private xAI large language models (LLMs) which appear to have been custom made for working with internal data from Musk's companies, including SpaceX, Tesla and Twitter/X, KrebsOnSecurity has learned.

A 23-year-old Scottish man thought to be a member of the prolific Scattered Spider cybercrime group was extradited last week from Spain to the United States, where he is facing charges of wire fraud, conspiracy and identity theft. U.S. prosecutors allege Tyler Robert Buchanan and co-conspirators hacked into dozens of companies in the United States and abroad, and that he personally controlled more than $26 million stolen from victims.

A whistleblower at the National Labor Relations Board (NLRB) alleged last week that denizens of Elon Musk's Department of Government Efficiency (DOGE) siphoned gigabytes of data from the agency's sensitive case files in early March. The whistleblower said accounts created for DOGE at the NLRB downloaded three code repositories from GitHub. Further investigation into one of those code bundles shows it is remarkably similar to a program published in January 2025 by Marko Elez, a 25-year-old DOGE employee who has worked at a number of Musk's companies.

A security architect with the National Labor Relations Board (NLRB) alleges that employees from Elon Musk's Department of Government Efficiency (DOGE) transferred gigabytes of sensitive data from agency case files in early March, using short-lived accounts configured to leave few traces of network activity. The NLRB whistleblower said the unusual large data outflows coincided with multiple blocked login attempts from an Internet address in Russia that tried to use valid credentials for a newly-created DOGE user account.

A critical resource that cybersecurity professionals worldwide rely on to identify, mitigate and fix security vulnerabilities in software and hardware is in danger of breaking down. The federally funded, non-profit research and development organization MITRE warned today that its contract to maintain the Common Vulnerabilities and Exposures (CVE) program -- which is traditionally funded each year by the Department of Homeland Security -- expires on April 16.