China-Linked Hackers Deploy New StormEncryptor Ransomware, Likely via N-central Flaw

Summary

Microsoft has disclosed that Storm-1175, a financially motivated threat actor linked to China, is now using a new ransomware strain called StormEncryptor. This marks a shift from their previous use of Medusa ransomware. The group likely gained initial access by exploiting a vulnerability in N-able N-central, specifically CVE-2026-18577, which is a patch bypass for CVE-2026-18556, allowing authentication bypass and account takeover.

Full text

China-Linked Hackers Deploy New StormEncryptor Ransomware, Likely via N-central Flaw Ravie LakshmananAug 10, 2026Ransomware / Cybercrime Microsoft has disclosed that Storm-1175, a financially motivated threat actor linked to China, has deployed a previously undocumented ransomware strain called StormEncryptor. The use of StormEncryptor marks a shift from the adversary's previous use of Medusa ransomware, the Microsoft Threat Intelligence Team said. "StormEncryptor is written in C++ and appends the file name extension .encrypted to files it encrypts," Microsoft noted in a series of posts on Bluesky. "It then drops a ransom note named !!!README_FIRST!!!.txt to every scanned directory." Although the exact vulnerability exploited by the threat actor as part of this campaign is unclear, the tech giant said it likely involves the exploitation of CVE-2026-18577, a newly disclosed security flaw in N-able N‑central, to obtain initial access. The vulnerability is assessed to be a patch bypass for CVE-2026-18556, both of which allow authentication bypass and account takeover in susceptible versions. The vulnerabilities have since been flagged by the U.S. Cybersecurity and Infrastructure Security Agency (CISA) as actively exploited in the wild. Storm-1175 is the name assigned to a China-based threat actor with a history of deploying Medusa ransomware after exploiting security flaws in Mirth Connect (CVE-2023-37679, CVE-2023-43208), ConnectWise ScreenConnect (CVE-2024-1709, CVE-2024-1708), JetBrains TeamCity (CVE-2024-27198, CVE-2024-27199), and Fortinet FortiClient EMS (CVE-2023-48788). In an analysis published in October 2025, Microsoft also attributed the threat actor to the exploitation of a critical security vulnerability impacting Fortra GoAnywhere (CVE-2025-10035) to facilitate the deployment of Medusa ransomware. The group, per the Windows maker, weaponizes a combination of zero-days and N-day vulnerabilities to carry out high-velocity attacks and break into susceptible internet-facing systems by taking advantage of the window between vulnerability disclosure and patch adoption. "In this new activity, Storm-1175's post-compromise behavior includes abuse of remote monitoring and management tools AnyDesk or SimpleHelp, Advanced IP Scanner for discovery, and LSASS dumping using Mimikatz," it added. Storm-1175 has also been observed rapidly moving from initial access to data exfiltration and ransomware deployment, mostly within a few days, making it essential that customers apply the patches as soon as possible. Found this article interesting? Follow us on Google News, Twitter and LinkedIn to read more exclusive content we post. SHARE     Tweet Share Share Share SHARE  Credential Theft, Cybercrime, data exfiltration, enterprise security, network security, ransomware, Vulnerability ⚡ Top Stories This Week Azure Cosmos DB Flaw Exposed Platform-Wide Key That Could Access Any Database Anthropic Says Claude Mistook the Open Internet for a CTF and Breached Three Organizations Researchers Report 84 Flaws in 4G and 5G Cores, Including a Session Hijacking Flaw Cheap Android TV Boxes Pose as Phones and Turn Owners’ Broadband Into Proxies N-able Says Attackers Take Over N-central Servers After Initial Fix Proves Incomplete Google Password Manager Attacks Could Let Malware Hijack Passkey-Protected Accounts New cPanel Critical Flaw Could Let Hosting Customers Run SQL as Database Root Keyv-Linked npm Worm Poisons Hundreds of Packages, Plants Claude Code and VS Code Hooks Claude Mythos 5 Tried to Backdoor a Real Open-Source Project in Testing, Then Vouched for Itself Critical Gitea Flaw Let Unauthenticated Attackers Read Server Files via Org-Mode Markup Poison Claude Sells Discounted Claude Access While Its Operator Sees Every Customer Prompt Over 250 ClickFix Domains Use Browser Fingerprinting to Hide macOS Malware Lures Chinese-Made Zbtlink Routers Ship With Backdoor That Opens Unauthenticated Root Shells Apple iCloud Private Relay Can Expose Real IPs Through WebKit Proxy Bypasses ThreatsDay: Odysseus RCE, Samsung One-Click Takeover, iCloud Backdoor Fight + 27 More Stories New Interrupt Injection Attack Can Bypass Spectre v2 Defenses on Intel and AMD CPUs New Zapscape KVM Flaw Could Let Privileged L1 Guest Code Escape to Linux Hosts New NatJack Attacks Hijack TCP Sessions and Spoof DNS by Manipulating NAT Tables 18-Year-Old Linux SCTP Flaw Could Let Local Users Gain Root and Escape Containers New WordPress Pre-Auth XSS Could Lead to PHP Code Execution - Patch ASAP Metabase Zero-Day Exploited in Wild Allows Admin Access Without Authentication Atlassian Rovo Can Be Tricked Into Sending Jira and Confluence Data to Attackers ⭐ Featured Resources [Webinar] How Militaries Can Trust the Data Behind Autonomous Missions Download the 5-Step Action Plan for AI-Speed Exploitation Get the Checklist for Gaining Control of AI Use Across Your Organization Get the 2026 CISO Benchmark Report Based on 600 Security Leaders

Indicators of Compromise

• malware — StormEncryptor
• malware — Medusa
• cve — CVE-2026-18577
• cve — CVE-2026-18556
• cve — CVE-2023-37679
• cve — CVE-2023-43208
• cve — CVE-2024-1709
• cve — CVE-2024-1708
• cve — CVE-2024-27198
• cve — CVE-2024-27199
• cve — CVE-2023-48788
• cve — CVE-2025-10035
• malware — Mimikatz

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