Daily CISO Briefing Note | December 10, 2025

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Summary

The past 48 hours included a monthly security update from a major operating system vendor addressing an actively exploited privilege escalation vulnerability, a vendor security patch from a network security company addressing authentication bypass in single sign-on configurations, security vendor research documenting infostealer malware distributed through a developer tool marketplace, a threat research report detailing a financially motivated campaign targeting Canadian organizations through recruitment platform abuse, and security vendor research describing a remote access trojan using blockchain infrastructure for command-and-control operations. These disclosures arose from unrelated sectors and appeared within the same reporting window through monthly patch cycles, coordinated disclosure timelines, and independent security research publication schedules.

Theme 1: Operating system vendor monthly security update addresses actively exploited privilege escalation vulnerability in cloud file synchronization driver

Microsoft released its December 2025 Patch Tuesday on December 9, addressing 57 vulnerabilities across Windows, Office, Exchange Server, and adjacent products. The most significant disclosure, CVE-2025-62221, affects the Windows Cloud Files Mini Filter Driver with a CVSS score of 7.8 and enables authenticated attackers to escalate privileges to SYSTEM through a use-after-free condition. Microsoft confirmed active exploitation prior to patch availability. The affected driver component remains present on Windows 10 and later systems regardless of whether cloud synchronization applications such as OneDrive, Google Drive, or iCloud are installed. Source category: vendor security bulletin. Executive relevance sits in the presence of the affected component across all modern Windows endpoints within enterprise environments connected to cloud storage and productivity ecosystems.

Theme 2: Network security vendor releases authentication bypass patch affecting single sign-on configurations in firewall and web application firewall products

Fortinet published security advisories on December 9 addressing CVE-2025-59718 and CVE-2025-59719, both rated CVSS 9.8, affecting FortiOS, FortiWeb, FortiProxy, and FortiSwitchManager. The vulnerabilities enable unauthenticated attackers to bypass FortiCloud single sign-on authentication through crafted SAML messages when the FortiCloud SSO login feature is enabled. Fortinet noted the feature is not enabled in default factory configurations but becomes active when administrators register devices to FortiCare without disabling the SSO toggle. Source category: vendor security bulletin. Executive relevance sits in the deployment of network security appliances registered to cloud management consoles where administrative authentication flows traverse federated identity pathways.

Theme 3: Security vendor research identifies information-stealing malware distributed through developer tool marketplace extensions

Security researchers at Koi Security disclosed that two extensions published to Microsoft's Visual Studio Code Marketplace, "Bitcoin Black" and "Codo AI," contained malware designed to capture screenshots, exfiltrate credentials, steal cryptocurrency wallet data, and hijack browser sessions. Both extensions were published under the developer name "BigBlack" and delivered payloads through DLL hijacking using a legitimate signed executable. Microsoft removed the extensions on December 5 and December 8 respectively. The malware harvested WiFi passwords, clipboard contents, and browser session cookies by launching Chrome and Edge in headless mode. Source category: security vendor research. Executive relevance sits in the integration of third-party extensions within software development environments where developers operate with elevated access to source code repositories and production deployment credentials.

Theme 4: Threat research report documents financially motivated campaign targeting Canadian organizations through recruitment platform abuse and custom ransomware deployment

Sophos published research on the GOLD BLADE threat group, also tracked as RedCurl and Earth Kapre, detailing nearly 40 intrusions between February 2024 and August 2025 with approximately 80 percent targeting Canadian organizations. The campaign employed weaponized resumes submitted directly to recruitment platforms including Indeed, JazzHR, and ADP WorkforceNow to deliver custom QWCrypt ransomware through multi-stage infection chains. The threat group deployed bring-your-own-vulnerable-driver techniques to disable endpoint security software and targeted virtualization infrastructure for maximum operational impact. Source category: security vendor research. Executive relevance sits in the exposure of human resources recruitment workflows as initial access vectors where hiring processes interface with external document submissions from untrusted sources.

Theme 5: Security vendor research describes remote access trojan using blockchain infrastructure for command-and-control operations following web framework vulnerability exploitation

Sysdig published research on December 8 documenting EtherRAT, a remote access trojan discovered targeting Next.js applications following exploitation of the React Server Components vulnerability CVE-2025-55182. The malware retrieves command-and-control server addresses from an Ethereum smart contract queried across nine public blockchain RPC endpoints using a consensus mechanism. Technical analysis revealed overlap with North Korean-linked Contagious Interview campaign tooling. The implant establishes persistence through five independent Linux mechanisms and downloads its own Node.js runtime from official distribution sources. Source category: security vendor research. Executive relevance sits in the deployment of web application frameworks built on React Server Components within environments where decentralized blockchain infrastructure complicates traditional network-based detection and interdiction approaches.

Synthesis

Operating system patch cycles, network security vendor disclosures, developer tool marketplace incidents, threat research publications, and web framework exploitation campaigns appeared within the same 48-hour reporting window through routine coordinated disclosure timelines and independent security research publication schedules. (8 themes excluded—covered in prior 48-hour briefings.)

Author
Daniel Michan is the founder of CybersecurityHQ, a CISO-grade intelligence platform read weekly across the Fortune 100. He analyzes identity-centric risk, machine identity failures, SaaS integration breakdowns, and emerging AI-speed threats, producing executive briefings and deep-dive research used by enterprise security leaders for decision support.