Executive Summary
In mid-2025, the Warlock ransomware group exploited unpatched Microsoft SharePoint servers to gain initial access to various organizations across North America, Europe, Asia, and Africa. Utilizing known vulnerabilities (CVE-2025-49704, CVE-2025-49706, CVE-2025-53770, and CVE-2025-53771), they deployed web shells via HTTP POST requests, enabling reconnaissance, credential theft, and lateral movement. The attack culminated in the deployment of ransomware, encrypting files with the .x2anylock extension and exfiltrating data using RClone. (clearphish.ai)
This incident underscores the critical importance of timely patch management, especially for widely used enterprise applications like SharePoint. The Warlock group's rapid escalation from forum discussions to impactful campaigns highlights the evolving threat landscape and the need for organizations to bolster their cybersecurity defenses against sophisticated ransomware operations.
Why This Matters Now
The Warlock ransomware group's exploitation of unpatched SharePoint servers in 2025 serves as a stark reminder of the vulnerabilities present in widely used enterprise applications. With the increasing sophistication of ransomware attacks and the potential for significant operational disruptions, organizations must prioritize timely patch management and robust cybersecurity measures to mitigate such threats.
Attack Path Analysis
The Warlock ransomware group exploited unpatched Microsoft SharePoint servers to gain initial access, then escalated privileges by activating and elevating the built-in 'guest' account. They moved laterally using tools like PsExec and Impacket, established command and control through TightVNC and Yuze, exfiltrated data using Rclone disguised as TrendSecurity.exe, and finally deployed ransomware to encrypt files, demanding ransom payments.
Kill Chain Progression
Initial Compromise
Description
Exploited unpatched Microsoft SharePoint servers to gain initial access.
Related CVEs
CVE-2025-53770
CVSS 9.8A remote code execution vulnerability in Microsoft SharePoint Server allows unauthenticated attackers to execute arbitrary code via specially crafted HTTP requests.
Affected Products:
Microsoft SharePoint Server – 2016, 2019, Subscription Edition
Exploit Status:
exploited in the wildCVE-2025-53771
CVSS 6.5A code injection vulnerability in Microsoft SharePoint Server allows attackers to execute arbitrary code by exploiting path traversal issues.
Affected Products:
Microsoft SharePoint Server – 2016, 2019, Subscription Edition
Exploit Status:
exploited in the wildCVE-2025-49704
CVSS 8.8A remote code execution vulnerability in Microsoft SharePoint Server allows authenticated attackers with Site Member permissions to execute arbitrary code.
Affected Products:
Microsoft SharePoint Server – 2016, 2019, Subscription Edition
Exploit Status:
exploited in the wildCVE-2025-49706
CVSS 6.5A spoofing vulnerability in Microsoft SharePoint Server allows attackers to bypass authentication via HTTP Referer spoofing to the ToolPane endpoint.
Affected Products:
Microsoft SharePoint Server – 2016, 2019, Subscription Edition
Exploit Status:
exploited in the wild
MITRE ATT&CK® Techniques
Exploit Public-Facing Application
Command and Scripting Interpreter
Create or Modify System Process: Windows Service
Impair Defenses: Disable or Modify Tools
Remote Services: Remote Desktop Protocol
Exfiltration Over Web Service: Exfiltration to Cloud Storage
Data Encrypted for Impact
Potential Compliance Exposure
Mapping incident impact across multiple compliance frameworks.
PCI DSS 4.0 – Ensure all system components are protected from known vulnerabilities by installing applicable security patches
Control ID: 6.2
NYDFS 23 NYCRR 500 – Cybersecurity Policy
Control ID: 500.03
DORA – ICT Risk Management Framework
Control ID: Article 10
CISA Zero Trust Maturity Model 2.0 – Implement strong authentication mechanisms
Control ID: Identity Pillar
NIS2 Directive – Cybersecurity Risk Management Measures
Control ID: Article 21
Sector Implications
Industry-specific impact of the vulnerabilities, including operational, regulatory, and cloud security risks.
Information Technology/IT
Critical risk from Warlock ransomware exploiting SharePoint vulnerabilities, requiring enhanced zero trust segmentation and egress security controls for infrastructure protection.
Government Administration
High-priority target for Warlock group with advanced BYOVD techniques, necessitating immediate SharePoint patching and multicloud visibility for national security assets.
Electrical/Electronic Manufacturing
Manufacturing sectors face lateral movement threats through compromised SharePoint servers, requiring east-west traffic security and anomaly detection capabilities for operational continuity.
Computer Software/Engineering
Software organizations vulnerable to encrypted traffic exploitation and persistent remote access tools, demanding inline IPS and threat detection for development environment protection.
Sources
- Warlock Ransomware Group Augments Post-Exploitation Activitieshttps://www.darkreading.com/threat-intelligence/warlock-ransomware-post-exploitation-activitiesVerified
- Disrupting active exploitation of on-premises SharePoint vulnerabilitieshttps://www.microsoft.com/en-us/security/blog/2025/07/22/disrupting-active-exploitation-of-on-premises-sharepoint-vulnerabilities/Verified
- Warlock Ransomware Exploits Unpatched SharePoint Servers in Global Attackshttps://www.clearphish.ai/news/warlock-ransomware-sharepoint-attacks-2025Verified
- Warlock Ransomware Hits SharePoint via Zero-Day Chainhttps://www.purple-ops.io/cybersecurity-threat-intelligence-blog/warlock-sharepoint-ransomware/Verified
Frequently Asked Questions
Cloud Native Security Fabric Mitigations and ControlsCNSF
Aviatrix Zero Trust CNSF is pertinent to this incident as it could have constrained the Warlock ransomware group's lateral movement and data exfiltration, thereby reducing the attack's overall impact.
Control: Cloud Native Security Fabric (CNSF)
Mitigation: While Aviatrix CNSF may not prevent initial exploitation of unpatched servers, it could limit the attacker's ability to move laterally from the compromised entry point.
Control: Zero Trust Segmentation
Mitigation: Aviatrix Zero Trust Segmentation could limit the attacker's ability to leverage elevated privileges to access other critical systems.
Control: East-West Traffic Security
Mitigation: Aviatrix East-West Traffic Security could constrain the attacker's ability to move laterally by monitoring and controlling internal traffic flows.
Control: Multicloud Visibility & Control
Mitigation: Aviatrix Multicloud Visibility & Control could detect and limit unauthorized command and control communications across cloud environments.
Control: Egress Security & Policy Enforcement
Mitigation: Aviatrix Egress Security & Policy Enforcement could limit unauthorized data exfiltration by monitoring and controlling outbound traffic.
While Aviatrix CNSF may not prevent the initial deployment of ransomware, it could limit the spread and impact by restricting lateral movement and data exfiltration.
Impact at a Glance
Affected Business Functions
- Document Management
- Collaboration Platforms
- Intranet Services
Estimated downtime: 14 days
Estimated loss: $500,000
Sensitive corporate documents, internal communications, and potentially customer data.
Recommended Actions
Key Takeaways & Next Steps
- • Implement Zero Trust Segmentation to restrict lateral movement and limit the spread of ransomware.
- • Deploy East-West Traffic Security controls to monitor and control internal network communications.
- • Utilize Egress Security & Policy Enforcement to prevent unauthorized data exfiltration.
- • Enhance Threat Detection & Anomaly Response capabilities to identify and respond to malicious activities promptly.
- • Regularly patch and update all systems, especially public-facing applications like SharePoint, to mitigate known vulnerabilities.
