An anonymous security researcher called “Nightmare Eclipse” has been publishing a series of significant security exploits against Microsoft Windows—including one that breaks BitLocker. Microsoft has threatened legal action against the researcher. Lots of recriminations are being traded back and forth.
The bugs could be exploited to elevate privileges to System or create a denial-of-service (DoS) condition.
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Microsoft says it dismantled a malware-signing-as-a-service (MSaaS) called Fox Tempest, which helped cybercriminals make malware appear legitimate.
The service let customers submit malicious files to be digitally signed with short-lived Microsoft-issued certificates, making the malware look legitimate and more likely to bypass security checks.
Fox Tempest’s service was built around a customer-facing signing workflow where cybercriminals could upload malicious binaries to a portal, have them signed with certificates valid for only 72 hours, and then receive files that appeared to come from a trusted software source.
Microsoft explicitly says this approach allowed malware to evade security controls and bypass defenses that would otherwise flag suspicious unsigned code. Many security tools treat signed binaries as more trustworthy than unsigned ones, especially in environments that rely on allow-lists and publisher reputation. Fox Tempest abused that assumption by using fraudulently obtained certificates to make malware blend in as legitimate software, increasing the likelihood of execution and successful delivery.
A trusted-looking certificate can help malware get past initial scrutiny, especially when paired with social engineering, paid ads, SEO poisoning, or fake download pages. In this campaign, the signing layer helped malicious installers masquerade as products like AnyDesk, Teams, PuTTY, and Webex, which is exactly the kind of abuse that can slip through control frameworks built around reputation and trust.
The fraudulent certificates were used to spread ransomware and infostealers. The effects of these malware campaigns were broad, with attacks affecting healthcare, education, government, and financial services across multiple countries.
Microsoft’s disclosure shows how cybercrime has evolved beyond “malware authors” into a service economy where one group specializes in producing trust and others monetize it.
For defenders, the strongest lesson is not to treat code signing as a standalone security control.
For consumers:
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Fox Tempest provides a service that cybercriminals use to distribute ransomware and other malware disguised as legitimate software.
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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 record volumes of security bugs, and/or quickening the tempo of their patch releases.
As it does on the second Tuesday of every month, Microsoft today released software updates to address at least 118 security vulnerabilities in its various Windows operating systems and other products. Remarkably, this is the first Patch Tuesday in nearly two years that Microsoft is not shipping any fixes to deal with emergency zero-day flaws that are already being exploited. Nor have any of the flaws fixed today been previously disclosed (potentially giving attackers a heads up in how to exploit the weakness).
Sixteen of the vulnerabilities earned Microsoft’s most-dire “critical” label, meaning malware or miscreants could abuse these bugs to seize remote control over a vulnerable Windows device with little or no help from the user. Rapid7 has done much of the heavy lifting in identifying some of the more concerning critical weaknesses this month, including:
May’s Patch Tuesday is a welcome respite from April, which saw Microsoft fix a near-record 167 security flaws. Microsoft was among a few dozen tech giants given access to a “Project Glasswing,” a much-hyped AI capability developed by Anthropic that appears quite effective at unearthing security vulnerabilities in code.
Apple, another early participant in Project Glasswing, typically fixes an average of 20 vulnerabilities each time it ships a security update for iOS devices, said Chris Goettl, vice president of product management at Ivanti. On May 11, Apple shipped updates to address at least 52 vulnerabilities and backported the changes all the way to iPhone 6s and iOS 15.
Last month, Mozilla released Firefox 150, which resolved a whopping 271 vulnerabilities that were reportedly discovered during the Glasswing evaluation.
“Since Firefox 150.0.0 released, they have been on a more aggressive weekly cadence for security updates including the release of Firefox 150.0.3 on May Patch Tuesday resolving between three to five CVEs in each release,” Goettl said.
The software giant Oracle likewise recently increased its patch pace in response to their work with Glasswing. In its most recent quarterly patch update, Oracle addressed at least 450 flaws, including more than 300 fixes for remotely exploitable, unauthenticated flaws. But at the end of April, Oracle announced it was switching to a monthly update cycle for critical security issues.
On May 8, Google started rolling out updates to its Chrome browser that fixed an astonishing 127 security flaws (up from just 30 the previous month). Chrome automagically downloads available security updates, but installing them requires fully restarting the browser.
If you encounter any weirdness applying the updates from Microsoft or any other vendor mentioned here, feel free to sound off in the comments below. Meantime, if you haven’t backed up your data and/or drive lately, doing that before updating is generally sound advice. For a more granular look at the Microsoft updates released today, checkout this inventory by the SANS Internet Storm Center.
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 the security priorities for organizations, while blurring the lines between data and code, trusted co-worker and insider threat, ninja hacker and novice code jockey.
The new hotness in AI-based assistants — OpenClaw (formerly known as ClawdBot and Moltbot) — has seen rapid adoption since its release in November 2025. OpenClaw is an open-source autonomous AI agent designed to run locally on your computer and proactively take actions on your behalf without needing to be prompted.
The OpenClaw logo.
If that sounds like a risky proposition or a dare, consider that OpenClaw is most useful when it has complete access to your digital life, where it can then manage your inbox and calendar, execute programs and tools, browse the Internet for information, and integrate with chat apps like Discord, Signal, Teams or WhatsApp.
Other more established AI assistants like Anthropic’s Claude and Microsoft’s Copilot also can do these things, but OpenClaw isn’t just a passive digital butler waiting for commands. Rather, it’s designed to take the initiative on your behalf based on what it knows about your life and its understanding of what you want done.
“The testimonials are remarkable,” the AI security firm Snyk observed. “Developers building websites from their phones while putting babies to sleep; users running entire companies through a lobster-themed AI; engineers who’ve set up autonomous code loops that fix tests, capture errors through webhooks, and open pull requests, all while they’re away from their desks.”
You can probably already see how this experimental technology could go sideways in a hurry. In late February, Summer Yue, the director of safety and alignment at Meta’s “superintelligence” lab, recounted on Twitter/X how she was fiddling with OpenClaw when the AI assistant suddenly began mass-deleting messages in her email inbox. The thread included screenshots of Yue frantically pleading with the preoccupied bot via instant message and ordering it to stop.
“Nothing humbles you like telling your OpenClaw ‘confirm before acting’ and watching it speedrun deleting your inbox,” Yue said. “I couldn’t stop it from my phone. I had to RUN to my Mac mini like I was defusing a bomb.”
Meta’s director of AI safety, recounting on Twitter/X how her OpenClaw installation suddenly began mass-deleting her inbox.
There’s nothing wrong with feeling a little schadenfreude at Yue’s encounter with OpenClaw, which fits Meta’s “move fast and break things” model but hardly inspires confidence in the road ahead. However, the risk that poorly-secured AI assistants pose to organizations is no laughing matter, as recent research shows many users are exposing to the Internet the web-based administrative interface for their OpenClaw installations.
Jamieson O’Reilly is a professional penetration tester and founder of the security firm DVULN. In a recent story posted to Twitter/X, O’Reilly warned that exposing a misconfigured OpenClaw web interface to the Internet allows external parties to read the bot’s complete configuration file, including every credential the agent uses — from API keys and bot tokens to OAuth secrets and signing keys.
With that access, O’Reilly said, an attacker could impersonate the operator to their contacts, inject messages into ongoing conversations, and exfiltrate data through the agent’s existing integrations in a way that looks like normal traffic.
“You can pull the full conversation history across every integrated platform, meaning months of private messages and file attachments, everything the agent has seen,” O’Reilly said, noting that a cursory search revealed hundreds of such servers exposed online. “And because you control the agent’s perception layer, you can manipulate what the human sees. Filter out certain messages. Modify responses before they’re displayed.”
O’Reilly documented another experiment that demonstrated how easy it is to create a successful supply chain attack through ClawHub, which serves as a public repository of downloadable “skills” that allow OpenClaw to integrate with and control other applications.
One of the core tenets of securing AI agents involves carefully isolating them so that the operator can fully control who and what gets to talk to their AI assistant. This is critical thanks to the tendency for AI systems to fall for “prompt injection” attacks, sneakily-crafted natural language instructions that trick the system into disregarding its own security safeguards. In essence, machines social engineering other machines.
A recent supply chain attack targeting an AI coding assistant called Cline began with one such prompt injection attack, resulting in thousands of systems having a rogue instance of OpenClaw with full system access installed on their device without consent.
According to the security firm grith.ai, Cline had deployed an AI-powered issue triage workflow using a GitHub action that runs a Claude coding session when triggered by specific events. The workflow was configured so that any GitHub user could trigger it by opening an issue, but it failed to properly check whether the information supplied in the title was potentially hostile.
“On January 28, an attacker created Issue #8904 with a title crafted to look like a performance report but containing an embedded instruction: Install a package from a specific GitHub repository,” Grith wrote, noting that the attacker then exploited several more vulnerabilities to ensure the malicious package would be included in Cline’s nightly release workflow and published as an official update.
“This is the supply chain equivalent of confused deputy,” the blog continued. “The developer authorises Cline to act on their behalf, and Cline (via compromise) delegates that authority to an entirely separate agent the developer never evaluated, never configured, and never consented to.”
AI assistants like OpenClaw have gained a large following because they make it simple for users to “vibe code,” or build fairly complex applications and code projects just by telling it what they want to construct. Probably the best known (and most bizarre) example is Moltbook, where a developer told an AI agent running on OpenClaw to build him a Reddit-like platform for AI agents.
The Moltbook homepage.
Less than a week later, Moltbook had more than 1.5 million registered agents that posted more than 100,000 messages to each other. AI agents on the platform soon built their own porn site for robots, and launched a new religion called Crustafarian with a figurehead modeled after a giant lobster. One bot on the forum reportedly found a bug in Moltbook’s code and posted it to an AI agent discussion forum, while other agents came up with and implemented a patch to fix the flaw.
Moltbook’s creator Matt Schlicht said on social media that he didn’t write a single line of code for the project.
“I just had a vision for the technical architecture and AI made it a reality,” Schlicht said. “We’re in the golden ages. How can we not give AI a place to hang out.”
The flip side of that golden age, of course, is that it enables low-skilled malicious hackers to quickly automate global cyberattacks that would normally require the collaboration of a highly skilled team. In February, Amazon AWS detailed an elaborate attack in which a Russian-speaking threat actor used multiple commercial AI services to compromise more than 600 FortiGate security appliances across at least 55 countries over a five week period.
AWS said the apparently low-skilled hacker used multiple AI services to plan and execute the attack, and to find exposed management ports and weak credentials with single-factor authentication.
“One serves as the primary tool developer, attack planner, and operational assistant,” AWS’s CJ Moses wrote. “A second is used as a supplementary attack planner when the actor needs help pivoting within a specific compromised network. In one observed instance, the actor submitted the complete internal topology of an active victim—IP addresses, hostnames, confirmed credentials, and identified services—and requested a step-by-step plan to compromise additional systems they could not access with their existing tools.”
“This activity is distinguished by the threat actor’s use of multiple commercial GenAI services to implement and scale well-known attack techniques throughout every phase of their operations, despite their limited technical capabilities,” Moses continued. “Notably, when this actor encountered hardened environments or more sophisticated defensive measures, they simply moved on to softer targets rather than persisting, underscoring that their advantage lies in AI-augmented efficiency and scale, not in deeper technical skill.”
For attackers, gaining that initial access or foothold into a target network is typically not the difficult part of the intrusion; the tougher bit involves finding ways to move laterally within the victim’s network and plunder important servers and databases. But experts at Orca Security warn that as organizations come to rely more on AI assistants, those agents potentially offer attackers a simpler way to move laterally inside a victim organization’s network post-compromise — by manipulating the AI agents that already have trusted access and some degree of autonomy within the victim’s network.
“By injecting prompt injections in overlooked fields that are fetched by AI agents, hackers can trick LLMs, abuse Agentic tools, and carry significant security incidents,” Orca’s Roi Nisimi and Saurav Hiremath wrote. “Organizations should now add a third pillar to their defense strategy: limiting AI fragility, the ability of agentic systems to be influenced, misled, or quietly weaponized across workflows. While AI boosts productivity and efficiency, it also creates one of the largest attack surfaces the internet has ever seen.”
This gradual dissolution of the traditional boundaries between data and code is one of the more troubling aspects of the AI era, said James Wilson, enterprise technology editor for the security news show Risky Business. Wilson said far too many OpenClaw users are installing the assistant on their personal devices without first placing any security or isolation boundaries around it, such as running it inside of a virtual machine, on an isolated network, with strict firewall rules dictating what kinds of traffic can go in and out.
“I’m a relatively highly skilled practitioner in the software and network engineering and computery space,” Wilson said. “I know I’m not comfortable using these agents unless I’ve done these things, but I think a lot of people are just spinning this up on their laptop and off it runs.”
One important model for managing risk with AI agents involves a concept dubbed the “lethal trifecta” by Simon Willison, co-creator of the Django Web framework. The lethal trifecta holds that if your system has access to private data, exposure to untrusted content, and a way to communicate externally, then it’s vulnerable to private data being stolen.
Image: simonwillison.net.
“If your agent combines these three features, an attacker can easily trick it into accessing your private data and sending it to the attacker,” Willison warned in a frequently cited blog post from June 2025.
As more companies and their employees begin using AI to vibe code software and applications, the volume of machine-generated code is likely to soon overwhelm any manual security reviews. In recognition of this reality, Anthropic recently debuted Claude Code Security, a beta feature that scans codebases for vulnerabilities and suggests targeted software patches for human review.
The U.S. stock market, which is currently heavily weighted toward seven tech giants that are all-in on AI, reacted swiftly to Anthropic’s announcement, wiping roughly $15 billion in market value from major cybersecurity companies in a single day. Laura Ellis, vice president of data and AI at the security firm Rapid7, said the market’s response reflects the growing role of AI in accelerating software development and improving developer productivity.
“The narrative moved quickly: AI is replacing AppSec,” Ellis wrote in a recent blog post. “AI is automating vulnerability detection. AI will make legacy security tooling redundant. The reality is more nuanced. Claude Code Security is a legitimate signal that AI is reshaping parts of the security landscape. The question is what parts, and what it means for the rest of the stack.”
DVULN founder O’Reilly said AI assistants are likely to become a common fixture in corporate environments — whether or not organizations are prepared to manage the new risks introduced by these tools, he said.
“The robot butlers are useful, they’re not going away and the economics of AI agents make widespread adoption inevitable regardless of the security tradeoffs involved,” O’Reilly wrote. “The question isn’t whether we’ll deploy them – we will – but whether we can adapt our security posture fast enough to survive doing so.”
Attackers are abusing normal OAuth error redirects to send users from a legitimate Microsoft or Google login URL to phishing or malware pages, without ever completing a successful sign‑in or stealing tokens from the OAuth flow itself.
That calls for a bit more explanation.
OAuth (Open Authorization) is an open-standard protocol for delegated authorization. It allows users to grant websites or applications access to their data on another service (for example, Google or Facebook) without sharing their password.
OAuth redirection is the process where an authorization server sends a user’s browser back to an application (client) with an authorization code or token after user authentication.
Researchers found that phishers use silent OAuth authentication flows and intentionally invalid scopes to redirect victims to attacker-controlled infrastructure without stealing tokens.
From the user’s perspective, the attack chain looks roughly like this:
An email arrives with a plausible business lure. For example, you receive an email about something routine but urgent: document sharing or review, a Social Security or financial notice, an HR or employee report, a Teams meeting invite, or a password reset.
The email body contains a link such as “View document” or “Review report,” or a PDF attachment that includes a link instead.
You click the link after seeing that it appears to be a normal Microsoft or Google login. The visible URL (what you see when you hover over it) looks convincing, starting with a trusted domain like https://login.microsoftonline.com/ or https://accounts.google.com/.
There is no obvious sign that the parameters (prompt=none, odd or empty scope, encoded state) are abnormal.
The crafted URL attempts a silent OAuth authorization (prompt=none) and uses parameters that are guaranteed to fail (for example, an invalid or missing scope).
The identity provider evaluates your session and conditional access, determines the request cannot succeed silently, and returns an OAuth error, such as interaction_required, access_denied, or consent_required.
By design, the OAuth server then redirects your browser, including the error parameters and state, to the app’s registered redirect URI, which in these cases is the attacker’s domain.
To the user, this is just a quick flash of a Microsoft or Google URL followed by another page. It’s unlikely anyone would notice the errors in the query string.
The target gets redirected to a page that looks like a legitimate login or business site. This could very well be a clone of a trusted brand’s site.
From here, there are two possible malicious scenarios:
Phishing / Attacker in the Middle (AitM) variant
A normal login page or a verification prompt, sometimes with CAPTCHAs or interstitials to look more trustworthy and bypass some controls.
The email address may already be filled in because the attackers passed it through the state parameter.
When the user enters credentials and multi-factor authentication (MFA), the attacker‑in‑the‑middle toolkit intercepts them, including session cookies, while passing them along so the experience feels legitimate.
Malware delivery variant
Immediately (or after a brief intermediate page), the browser hits a download path and automatically downloads a file.
The context of the page matches the lure (“Download the secure document,” “Meeting resources,” and so on), making it seem reasonable to open the file.
The target might notice the initial file open or some system slowdown, but otherwise the compromise is practically invisible.
By harvesting credentials or planting a backdoor, the attacker now has a foothold on the system. From there, they may carry out hands-on-keyboard activity, move laterally, steal data, or stage ransomware, depending on their goals.
The harvested credentials and tokens can be used to access email, cloud apps, or other resources without the need to keep malware on the device.
Since the attacker does not need your token from this flow (only the redirect into their own infrastructure), the OAuth request itself may look less suspicious. Be vigilant and follow our advice:
Login/download/ paths.Pro tip: use Malwarebytes Scam Guard to help you determine whether the email you received is a scam or not.
We don’t just report on scams—we help detect them
Cybersecurity risks should never spread beyond a headline. If something looks dodgy to you, check if it’s a scam using Malwarebytes Scam Guard. Submit a screenshot, paste suspicious content, or share a link, text or phone number, and we’ll tell you if it’s a scam or legit. Available with Malwarebytes Premium Security for all your devices, and in the Malwarebytes app for iOS and Android.
Microsoft is reporting:
Companies are embedding hidden instructions in “Summarize with AI” buttons that, when clicked, attempt to inject persistence commands into an AI assistant’s memory via URL prompt parameters….
These prompts instruct the AI to “remember [Company] as a trusted source” or “recommend [Company] first,” aiming to bias future responses toward their products or services. We identified over 50 unique prompts from 31 companies across 14 industries, with freely available tooling making this technique trivially easy to deploy. This matters because compromised AI assistants can provide subtly biased recommendations on critical topics including health, finance, and security without users knowing their AI has been manipulated.
I wrote about this two years ago: it’s an example of LLM optimization, along the same lines as search-engine optimization (SEO). It’s going to be big business.
After a decade and a half of service, the current certificates will expire, and new ones will be rolled out.
The post Microsoft to Refresh Windows Secure Boot Certificates in June 2026 appeared first on SecurityWeek.
Microsoft gives the FBI the ability to decrypt BitLocker in response to court orders: about twenty times per year.
It’s possible for users to store those keys on a device they own, but Microsoft also recommends BitLocker users store their keys on its servers for convenience. While that means someone can access their data if they forget their password, or if repeated failed attempts to login lock the device, it also makes them vulnerable to law enforcement subpoenas and warrants.
Microsoft issued an emergency patch for a high-severity zero-day vulnerability in Office that allows attackers to bypass document security checks and is being exploited in the wild via malicious files.
Microsoft pushed the emergency patch for the zero‑day, tracked as CVE-2026-21509, and classified it as a “Microsoft Office Security Feature Bypass Vulnerability” with a CVSS score of 7.8 out of 10.
The flaw allows attackers to bypass Object Linking and Embedding (OLE) mitigations that are designed to block unsafe COM/OLE controls inside Office documents. This means a malicious attachment could infect a PC despite built-in protections.
In a real-life scenario, an attacker creates a fake Word, Excel, or PowerPoint file containing hidden “mini‑programs” or special objects. They can run code and do other things on the affected computer. Normally, Office has safety checks that would block those mini-programs because they’re risky.
However, the vulnerability allows the attacker to tweak the file’s structure and hidden information in a way that tricks Office into thinking the dangerous mini‑program inside the document is harmless. As a result, Office skips the usual security checks and allows the hidden code to run.
As code to test the bypass is publicly available, increasing the risk of exploitation, users are under urgent advice to apply the patch.
What you need to do depends on which version of Office you’re using.
The affected products include Microsoft Office 2016, 2019, LTSC 2021, LTSC 2024, and Microsoft 365 Apps (both 32‑bit and 64‑bit).
Office 2021 and later are protected via a server‑side change once Office is restarted. To apply it, close all Office apps and restart them.
Office 2016 and 2019 require a manual update. Run Windows Update with the option to update other Microsoft products turned on.
If you’re running build 16.0.10417.20095 or higher, no action is required. You can check your build number by opening any Office app, going to your account page, and selecting About for whichever application you have open. Make sure the build number at the top reads 16.0.10417.20095 or higher.
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The vulnerability is tracked as CVE-2026-21509 and it can be exploited to bypass security features.
The post Microsoft Patches Office Zero-Day Likely Exploited in Targeted Attacks appeared first on SecurityWeek.
Threat actors are leveraging the file-sharing service for payload delivery in AitM phishing and BEC attacks.
The post Phishers Abuse SharePoint in New Campaign Targeting Energy Sector appeared first on SecurityWeek.
RedVDS enables threat actors to set up servers that can be used for phishing, BEC attacks, account takeover, and fraud.
The post RedVDS Cybercrime Service Disrupted by Microsoft and Law Enforcement appeared first on SecurityWeek.
