Google’s Chromium Bug Leak Exposes Unfixed JavaScript Execution Flaw Google accidentally leaked details of an unfixed vulnerability in Chromium that allows JavaScript to run persistently in the background even after the browser is closed enabling remote code execution (RCE) on affected devices. The flaw, reported by security researcher Lyra Rebane in December 2022, was initially acknowledged but remains unresolved despite multiple attempts to patch it. The vulnerability stems from a malicious webpage exploiting a Service Worker to maintain active JavaScript execution. Attackers could use this to turn browsers into unwitting participants in a botnet, capable of launching DDoS attacks, proxying malicious traffic, or redirecting users to targeted sites. Rebane demonstrated that the exploit could silently persist in Microsoft Edge without triggering download prompts, making it harder to detect. The issue affects all Chromium-based browsers, including Google Chrome, Microsoft Edge, Brave, Opera, Vivaldi, and Arc. Despite being marked as "fixed" in February 2024 under Google’s Vulnerability Rewards Program (VRP) with Rebane awarded a $1,000 bounty the patch was incomplete. On May 20, 2024, after the bug’s details were mistakenly made public, Rebane confirmed the exploit still worked in Chrome Dev 150 and Edge 148, calling it a "completely silent JS RCE" that activates from a single website visit. While the flaw does not bypass browser security boundaries or grant access to emails, files, or the host OS, its public exposure increases the risk of widespread exploitation. Google has since reclassified the issue as private, but the leak may accelerate the release of an emergency fix. No official response from Google has been provided as of publication.

New VoidStealer Malware Exploits Chrome’s App-Bound Encryption to Steal User Data A recently identified malware strain, VoidStealer, is targeting Google Chrome users on Windows, employing a sophisticated method to circumvent one of the browser’s critical security defenses. The malware specifically exploits Chrome’s App-Bound Encryption, a feature introduced by Google to safeguard stored passwords and session cookies from unauthorized access. Unlike traditional malware that relies on elevated system privileges, VoidStealer operates without requiring admin-level access, making it a particularly stealthy threat. The malware’s ability to bypass Chrome’s encryption layer highlights a growing trend in cybercriminal tactics, where attackers increasingly focus on browser-stored credentials as a high-value target. The discovery underscores the evolving nature of information-stealing malware, which continues to refine techniques to evade detection and extract sensitive data. While the exact distribution methods remain unclear, the emergence of VoidStealer serves as a reminder of the persistent risks posed by credential theft in modern cyberattacks.

Critical Zero-Day Vulnerability in Google Chrome Exploited in the Wild A newly discovered zero-day vulnerability in Google Chrome, tracked as CVE-2026-5281, is under active exploitation, posing severe risks to users globally. The flaw, a Use-After-Free (UAF) bug in Google Dawn an open-source WebGPU implementation allows attackers to bypass security protections and execute arbitrary code on affected systems. The vulnerability was added to the Known Exploited Vulnerabilities (KEV) catalog on April 1, 2026, prompting urgent calls for updates. Exploitation requires tricking a victim into visiting a malicious HTML page, which triggers the UAF bug, enabling attackers to compromise the system, steal data, or deploy malware. For enterprises, a single compromised browser could serve as an entry point for lateral movement across networks. While the advisory focuses on Google Chrome, the flaw affects all Chromium-based browsers, including Microsoft Edge, Opera, Vivaldi, and Brave, due to its presence in the underlying engine. Security researchers have not yet confirmed whether the vulnerability is being used in ransomware campaigns, but its active exploitation elevates it to a high-priority threat. The Cybersecurity and Infrastructure Security Agency (CISA) has mandated Federal Civilian Executive Branch (FCEB) agencies to mitigate the risk by April 15, 2026, under Binding Operational Directive (BOD) 22-01. Organizations and users are advised to apply vendor-provided patches immediately, prioritize browser updates in patch management cycles, and discontinue use of unpatched versions if mitigations are unavailable.

Google Patches Actively Exploited Chrome Zero-Day (CVE-2026-2441) On February 16, 2026, Google released an emergency security update to address CVE-2026-2441, a high-severity zero-day vulnerability in Chrome actively exploited in the wild. The flaw, classified as a use-after-free bug in the browser’s CSS component, allows remote attackers to execute arbitrary code within a sandbox via a maliciously crafted HTML page. The vulnerability was discovered and reported by security researcher Shaheen Fazim on February 11, 2026. While Google confirmed the existence of an exploit, details about the threat actor or attack methods remain undisclosed. This marks the first actively exploited Chrome zero-day of 2026, following eight similar vulnerabilities patched in 2025. The update (Chrome 145.0.7632.75/76 for Windows and Mac, 144.0.7559.75 for Linux) is rolling out globally over the coming days. Users of Chromium-based browsers, including Microsoft Edge, Brave, Opera, and Vivaldi, are advised to apply updates as they become available. The flaw’s severity underscores the ongoing risk of browser-based attacks, particularly those leveraging memory corruption vulnerabilities. No additional technical or attribution details have been released.

AI-Powered Browsers Introduce New Enterprise Security Risks Security researchers have uncovered vulnerabilities in AI-powered browsers and assistants, exposing enterprises to heightened risks of data breaches and unauthorized access. A key concern is prompt injection attacks, where malicious instructions embedded in web pages, emails, or documents trick AI agents into executing unintended commands bypassing security guardrails. Last year, Brave Software revealed that Perplexity’s Comet AI assistant failed to distinguish between legitimate user commands and hidden malicious prompts, potentially exposing sensitive data like bank accounts, emails, and cloud storage. While Perplexity later implemented real-time prompt injection classifiers, OpenAI acknowledged in December that such threats remain persistent, comparing them to social engineering attacks with no definitive solution. Gartner has advised CISOs to block AI browsers with agentic capabilities until enterprise-ready alternatives emerge, citing privacy risks from cloud-stored browsing data and third-party tracking. A 2025 University of California, Davis study found that generative AI browser assistants collect and share personal and sensitive information with both first-party servers and third-party trackers like Google Analytics. Unlike traditional browser threats, prompt injection attacks are easier to execute using natural language, requiring no advanced technical skills. A 2025 Gartner report found that 32% of organizations have already experienced such attacks on GenAI applications. Palo Alto Networks warns that these attacks can manipulate AI agents into leaking data, escalating privileges, or abusing connected systems often undetected by conventional security tools. Enterprises face additional risks from shadow AI unauthorized AI browser usage that creates blind spots for IT teams. IBM’s 2025 Cost of Data Breach report attributed 20% of breaches to shadow AI incidents. Compounding the issue, AI agents often operate with excessive permissions, violating the principle of least privilege, while Model Context Protocol (MCP) supply chain attacks introduce new attack vectors through third-party API integrations. To mitigate risks, security experts recommend: - Isolating agentic AI capabilities from routine browsing to prevent accidental exposure. - Enterprise-grade AI browsers with runtime security to monitor prompts and block malicious interactions. - Step-up MFA and human approval for sensitive actions, ensuring oversight before data transfers or transactions. - Defensive AI agents to detect anomalous behavior in primary browser agents. While AI browsers enhance productivity, their broad access and evolving attack surfaces demand stricter governance, visibility, and security controls to prevent exploitation.

New Windows Stealer "BoryptGrab" Spreads via Fake GitHub Repositories in Large-Scale Campaign A sophisticated malware campaign is distributing BoryptGrab, a Windows information stealer, through fake GitHub repositories masquerading as free tools, game cheats, and cracked software. The operation, active since at least April 2025, leverages SEO-optimized README files to rank malicious repositories near legitimate projects in search results, tricking users into downloading infected ZIP archives. ### How the Attack Works Attackers have created over 100 public GitHub repositories advertising enticing but fake software, including: - "Voicemod Pro download tool" - "Valorant performance boost" - "CS2 skin changers" - Cracked utilities and cheat-style tools Victims are redirected through GitHub-hosted pages containing Russian-language comments and base64/AES-based URL redirection logic, ultimately landing on a fake GitHub download page that dynamically generates a malicious ZIP file. ### Infection Chain & Malware Capabilities Once executed, the malware employs multiple infection vectors: - DLL side-loading (via a malicious `libcurl.dll` that decrypts an embedded launcher using XOR + AES-CBC). - VBS/PowerShell downloaders that bypass security controls (e.g., adding Microsoft Defender exclusions) and fetch the BoryptGrab stealer from attacker-controlled servers. - Golang-based downloader (HeaconLoad), which persists via Run-key registry entries and scheduled tasks, beaconing to command-and-control (C2) servers on port 8088. - TunnesshClient, a PyInstaller-packed backdoor that establishes reverse SSH tunnels, allowing attackers to execute commands, exfiltrate files, or use the victim as a SOCKS5 proxy. Some variants also deliver obfuscated Vidar stealer payloads via an `/api/custom_exe?build={BUILD_NAME}` endpoint, using XOR encryption and dynamic API resolution to evade detection. ### What BoryptGrab Steals The C/C++-based stealer includes anti-VM and anti-analysis checks and targets: - Browser data (Chrome, Edge, Firefox, Opera, Brave, Vivaldi, Yandex, etc.), including stored passwords (bypassing Chrome’s App-Bound Encryption). - Cryptocurrency wallets (Exodus, Electrum, Ledger Live, Atomic, Binance, Trezor, and dozens more). - System details, screenshots, Telegram data, and Discord tokens. - Files with specific extensions (via a "Filegraber" module). - Installed applications and hardcoded timestamps. Collected data is compressed and exfiltrated to attacker servers, often followed by the deployment of TunnesshClient for persistent remote access. ### Attribution & Infrastructure - Russian-language comments and log strings in malware components, along with Russian-hosted IP addresses, suggest a Russian-speaking threat actor, though formal attribution remains unconfirmed. - C2 servers communicate over ports 5466 and 8088, with build names (e.g., Shrek, Leon, CryptoByte, Sonic, Yaropolk) used to track infection branches. The campaign demonstrates a mature, evolving ecosystem, combining SEO poisoning, multi-stage downloaders, and SSH-based backdoors to maximize persistence and data theft.