Microsoft Breach Incident Score: Analysis & Impact (MIC1133111112125)

In this Rankiteo incident briefing, we review the Microsoft breach identified under incident ID MIC1133111112125.

The analysis begins with a detailed overview of Microsoft's information like the linkedin page: https://www.linkedin.com/company/github, the number of followers: 26897413, the industry type: Software Development and the number of employees: 220893 employees

After the initial compromise, the video explains how Rankiteo's incident engine converts technical details into a normalized incident score. The incident score before the incident was 591 and after the incident was 591 with a difference of 0 which is could be a good indicator of the severity and impact of the incident.

In the next step of the video, we will analyze in more details the incident and the impact it had on Microsoft and their customers.

On 12 August 2025, Microsoft disclosed Vulnerability and Remote Code Execution (RCE) issues under the banner "Critical Remote Code Execution Vulnerability in Windows Graphics Component (CVE-2025-50165)".

Zscaler ThreatLabz discovered CVE-2025-50165, a critical remote code execution (RCE) vulnerability affecting the Windows Graphics Component with a CVSS score of 9.8.

The disruption is felt across the environment, affecting Windows 11 Version 24H2 (x64), Windows 11 Version 24H2 (ARM64) and Windows Server 2025.

In response, moved swiftly to contain the threat with measures like Patch deployment (build 10.0.26100.4946), and began remediation that includes Immediate patching of all affected Windows systems and Prioritization of Windows infrastructure updates, and stakeholders are being briefed through Public advisory via Microsoft Security Update Guide and Urgent recommendation for 48-hour patch deployment.

The case underscores how Resolved (Patch released; no active exploitation reported), teams are taking away lessons such as Critical vulnerabilities in core system components (e.g., windowscodecs.dll) require accelerated patch management due to their broad attack surface. Default security mechanisms (e.g., CFG) may not be enabled in all architectures (32-bit vs. 64-bit), increasing exploitation risk. Proactive fuzzing and third-party research (e.g., Zscaler) play a key role in identifying high-severity flaws before widespread exploitation, and recommending next steps like Apply Microsoft patch (build 10.0.26100.4946) immediately across all affected systems, Prioritize patching for systems processing untrusted images/documents (e.g., email servers, shared drives) and Enable Control Flow Guard (CFG) where possible to mitigate ROP-based exploits, with advisories going out to stakeholders covering Microsoft urged all organizations to treat this as a critical priority and verify patch deployment within 48 hours.

Finally, we try to match the incident with the MITRE ATT&CK framework to see if there is any correlation between the incident and the MITRE ATT&CK framework.

The MITRE ATT&CK framework is a knowledge base of techniques and sub-techniques that are used to describe the tactics and procedures of cyber adversaries. It is a powerful tool for understanding the threat landscape and for developing effective defense strategies.

Rankiteo's analysis has identified several MITRE ATT&CK tactics and techniques associated with this incident, each with varying levels of confidence based on available evidence. Under the Initial Access tactic, the analysis identified Phishing: Spearphishing Attachment (T1566.001) with high confidence (95%), with evidence including weaponized document with malicious JPEG triggering RCE via windowscodecs.dll, and minimal user interaction (e.g., opening a document) and Supply Chain Compromise: Compromise Software Dependencies (T1195.002) with high confidence (90%), supported by evidence indicating windowscodecs.dll used by Microsoft Office and other apps creates widespread attack surface. Under the Execution tactic, the analysis identified Exploitation for Client Execution (T1203) with high confidence (100%), with evidence including remote Code Execution (RCE) via malicious JPEG in windowscodecs.dll, and heap spraying with ROP bypassing Control Flow Guard (CFG) and Command and Scripting Interpreter: Visual Basic (T1059.005) with moderate to high confidence (70%), supported by evidence indicating microsoft Office (commonly using VBA macros) as a vector for weaponized documents. Under the Privilege Escalation tactic, the analysis identified Exploitation for Privilege Escalation (T1068) with high confidence (90%), with evidence including full system compromise via arbitrary code execution in core Windows component, and bypasses CFG in 32-bit systems by default. Under the Defense Evasion tactic, the analysis identified Exploitation for Defense Evasion (T1211) with high confidence (95%), with evidence including heap spraying with ROP to bypass CFG, and uninitialized memory pointer dereference evades standard mitigations and Obfuscated Files or Information: Compile After Delivery (T1027.004) with moderate to high confidence (80%), supported by evidence indicating malicious JPEG embedded in documents, triggering runtime compilation/execution. Under the Lateral Movement tactic, the analysis identified Remote Services: SMB/Windows Admin Shares (T1021.002) with moderate to high confidence (75%), with evidence including potential lateral movement post-exploitation on Windows systems, and server Core installations vulnerable (common in enterprise networks). Under the Impact tactic, the analysis identified Data Encrypted for Impact (T1486) with moderate to high confidence (85%), supported by evidence indicating ransomware deployment listed as potential post-exploitation impact and Inhibit System Recovery (T1490) with moderate to high confidence (80%), supported by evidence indicating full system compromise could disable recovery mechanisms. Under the Persistence tactic, the analysis identified Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder (T1547.001) with moderate to high confidence (70%), supported by evidence indicating arbitrary code execution in core Windows component could enable persistence. These correlations help security teams understand the attack chain and develop appropriate defensive measures based on the observed tactics and techniques.