Incident Score: Analysis & Impact (INF1784716085)
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Rankiteo Score Impact Analysis
Key Highlights From The Incident Analysis
- Timeline of Infoblox's Cyber Attack and lateral movement inside company's environment.
- Overview of affected data sets, including SSNs and PHI, and why they materially increase incident severity.
- How Rankiteo’s incident engine converts technical details into a normalized incident score.
- How this cyber incident impacts Infoblox Rankiteo cyber scoring and cyber rating.
- Rankiteo’s MITRE ATT&CK correlation analysis for this incident, with associated confidence level.
Full Incident Analysis Transcript
In this Rankiteo incident briefing, we review the Infoblox breach identified under incident ID INF1784716085.
The analysis begins with a detailed overview of Infoblox's information like the linkedin page: https://www.linkedin.com/company/infoblox, the number of followers: 222669, the industry type: Computer and Network Security and the number of employees: 3366 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 754 and after the incident was 735 with a difference of -19 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 Infoblox and their customers.
A newly reported cybersecurity incident, "Sophisticated AiTM Phishing Campaign Hijacks Microsoft 365 Sessions via Compromised Outlook Accounts", has drawn attention.
In May 2026, security researchers at Infoblox uncovered a highly targeted adversary-in-the-middle (AiTM) phishing campaign abusing Microsoft Outlook mailboxes to steal multi-factor authenticated (MFA) Microsoft 365 sessions.
The disruption is felt across the environment, affecting Microsoft 365 (Outlook, SharePoint), internal communication channels, and exposing Microsoft 365 session cookies, credentials, Outlook emails, SharePoint files, SaaS application access.
Formal response steps have not been shared publicly yet.
The case underscores how Ongoing (as of disclosure), teams are taking away lessons such as Traditional defenses (MFA, URL filtering, domain reputation) are insufficient against AiTM attacks. Session-based compromises require continuous monitoring and conditional access policies to limit stolen session lifespans, and recommending next steps like Implement DNS-based threat intelligence to detect infrastructure reuse and subdomain patterns, Monitor Microsoft 365 sign-in behaviors for anomalous session activity and Enforce conditional access policies to limit the lifespan of stolen sessions.
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.
MITRE ATT&CK® Correlation Analysis
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 Link (T1566.002) with high confidence (95%), supported by evidence indicating procurement-themed phishing emails (e.g., RFIs, bid invitations) from compromised Outlook accounts and Trusted Relationship (T1199) with high confidence (90%), supported by evidence indicating abusing trusted internal communication channels to spread, leveraging compromised mailboxes. Under the Execution tactic, the analysis identified User Execution: Malicious Link (T1204.001) with high confidence (90%), supported by evidence indicating victims who click embedded links are redirected to fake document portals and spoofed login pages. Under the Credential Access tactic, the analysis identified Adversary-in-the-Middle: LLMNR/NBT-NS Poisoning and SMB Relay (T1557.001) with moderate to high confidence (80%), supported by evidence indicating aiTM phishing campaign using reverse proxy kits (EvilProxy, FlowerStorm, Kali365) to intercept credentials, Steal Web Session Cookie (T1539) with high confidence (95%), supported by evidence indicating steal multi-factor authenticated (MFA) Microsoft 365 sessions via session cookies, and Brute Force: Password Guessing (T1110.001) with lower confidence (30%), supported by evidence indicating no direct evidence, but phishing often precedes credential brute-forcing. Under the Lateral Movement tactic, the analysis identified Use Alternate Authentication Material: Web Session Cookie (T1550.004) with high confidence (95%), supported by evidence indicating reuse compromised mailboxes to send new phishing emails, extending attack chain and Remote Services: SMB/Windows Admin Shares (T1021.002) with moderate confidence (50%), supported by evidence indicating no direct evidence, but lateral movement via internal systems is implied. Under the Collection tactic, the analysis identified Email Collection: Remote Email Collection (T1114.002) with high confidence (90%), supported by evidence indicating access to Outlook emails, SharePoint files, and SaaS applications and Data from Information Repositories: SharePoint (T1213.002) with moderate to high confidence (85%), supported by evidence indicating full access to SharePoint and Microsoft 365 resources. Under the Exfiltration tactic, the analysis identified Exfiltration Over C2 Channel (T1041) with moderate to high confidence (80%), supported by evidence indicating data exfiltration and payroll fraud enabled by stolen session cookies and Transfer Data to Cloud Account (T1537) with moderate to high confidence (70%), supported by evidence indicating attackers gain access to SaaS applications, implying potential cloud exfiltration. Under the Defense Evasion tactic, the analysis identified Modify Authentication Process: Multi-Factor Authentication (T1556.006) with high confidence (95%), supported by evidence indicating mFA protections rendered ineffective via reverse proxy interception of authentication flows, Masquerading: Match Legitimate Name or Location (T1036.005) with high confidence (90%), supported by evidence indicating phishing emails mimic routine business workflows, use aged legitimate-looking domains, and Impair Defenses: Disable or Modify Tools (T1562.001) with moderate confidence (50%), supported by evidence indicating traditional defenses (MFA, URL filtering) struggle against AiTM attacks. Under the Command and Control tactic, the analysis identified Application Layer Protocol: Web Protocols (T1071.001) with high confidence (90%), supported by evidence indicating reverse proxy kits (EvilProxy, FlowerStorm, Kali365) intercept and proxy authentication flows and Proxy: External Proxy (T1090.002) with high confidence (95%), supported by evidence indicating attackers use reverse proxies to hijack sessions and bypass MFA. Under the Impact tactic, the analysis identified Defacement: Internal Defacement (T1491.001) with moderate confidence (60%), supported by evidence indicating abuse of trusted communication channels may involve defacement of internal trust and Account Access Removal (T1531) with moderate to high confidence (70%), supported by evidence indicating full identity inheritance via session cookies enables account takeovers. These correlations help security teams understand the attack chain and develop appropriate defensive measures based on the observed tactics and techniques.
Sources & References
- Infoblox Rankiteo Cyber Incident Details: https://www.rankiteo.com/company/infoblox/incident/INF1784716085
- Infoblox CyberSecurity Rating page: https://www.rankiteo.com/company/infoblox
- Infoblox Rankiteo Cyber Incident Blog Article: https://blog.rankiteo.com/inf1784716085-infoblox-cyber-attack-may-2026/
- Infoblox CyberSecurity Score History: https://www.rankiteo.com/company/infoblox/history
- Infoblox CyberSecurity Incident Source: https://cybersecuritynews.com/hackers-compromised-outlook-accounts/
- Rankiteo A.I CyberSecurity Rating methodology: https://www.rankiteo.com/Images/rankiteo_algo.pdf
- Rankiteo TPRM Scoring methodology: https://static.rankiteo.com/model/rankiteo_tprm_methodology.pdf