Microsoft Threat Intelligence is tracking an active supply chain attack in which a threat actor compromised the trusted OAuth App of the backup application ConnectWise Cloud Backup (AppId: 506e08f9-6e9a-4da4-942b-a099a03644ae), formerly SkyKick Backup, to obtain access tokens across customer tenants. ConnectWise Cloud Backup is a multitenant vendor application; customers grant consent for the application to operate in their tenants. We assess that the threat actor likely abused permissions previously granted by customers to the application, including highly elevated permissions like Directory.ReadWrite.All. On October 15, 2026, we observed broad successful service principal authentication originating from the IP address 144.172.64[.]128. Follow-on activity included Microsoft Graph API reconnaissance and attempts to add additional credentials on the related service principal in target tenants to maintain direct access as a backdoor. Microsoft Defender detects post-exploitation activity with the following alerts: - Any alert related to "Suspicious sign-in" - Graph API activity from a Microsoft threat intelligence IP address - Verified Threat Actor IP Defenders should review service principal sign-ins from unrecognized IP addresses, app credential changes, and OAuth grant activity associated with this specific OAuth AppId. In addition, we recommend looking for Threat Intelligence alerts on matching of IP against the Graph API activity and service principal activities. We will continue to monitor this incident and will share updates as they become available. We encourage customers to check ConnectWise advisory for more information and additional guidance: msft.it/6013aQBvV. Indicators of compromise (IOCs): - App name: ConnectWise Cloud Backup - AppId: 506e08f9-6e9a-4da4-942b-a099a03644ae - Publisher name: SkyKick - Source IP: 144.172.64[.]128 - User agents: Python-urllib/3.12, python-requests/2.31, python-requests/2.34.2

The October 2026 security updates are available. In addition, starting today, Microsoft is publishing Vulnerability Exploitability eXchange (VEX) statements for all Microsoft-assigned CVEs. Learn more: msft.it/6013aSA6V

Post-quantum cryptography readiness goes beyond protecting encrypted data. Authentication systems must evolve, too, and organizations should start preparing now. msft.it/6012aUw5n Organizations can begin inventorying certificate dependencies, assessing vendor roadmaps, identifying long-lived infrastructure, and creating non-production test environments. Early testing can surface compatibility and process gaps before post-quantum authentication is required at scale. Read the blog for practical guidance and learn how Microsoft’s PQC TLS Pilot Program supports eligible certificate authorities in controlled, non-production testing.

AI is accelerating familiar threats while giving defenders new ways to respond. This is a central theme of the 2026 Microsoft Digital Defense Report (MDDR), discussed in this episode of the Microsoft Threat Intelligence Podcast. msft.it/6019aoYQR Elliot Volkman speaks with Chloé Messdaghi, MDDR lead, and Karen Frost, Principal Security Researcher, about the intelligence behind the report’s findings and what they mean for security leaders. The conversation examines how AI is changing the speed, scale, and sophistication of threat actor activity, while noting that human direction still plays a meaningful role in attacks. For defenders, the discussion emphasizes the importance of connecting signals rather than simply collecting more of them. Correlating activity across identities, systems, and infrastructure can provide a fuller picture of an intrusion, while AI can help teams process threat information and detect, analyze, and respond at greater scale. For security leaders, the episode connects these findings to practical priorities, including phishing-resistant multifactor authentication, incident response plans, and governance and data access controls for AI. Listen to the podcast episode to hear more about understanding dependencies across an organization’s ecosystem and measuring security progress through risk reduction, not just the volume of security activity. Read the full 2026 Microsoft Digital Defense Report: msft.it/6010aoYQr

Storm-2945, a sub-cluster of the Russian state actor Midnight Blizzard, has resumed their CaptiveCrunch campaign. msft.it/6019aWMDf First reported by Microsoft Threat Intelligence in July 2026, the campaign uses manipulated network traffic and captive portals in the hospitality sector to gain access to targets. The renewed activity is consistent with reporting from Black Lotus Labs suggesting that multiple managed service providers are implicated; Storm-2945’s continued access to these upstream providers has likely enabled this rapid re-deployment. We have updated our blog to provide more recent network infrastructure indicators, detections, and hunting guidance. We want to thank Google Threat Intelligence Group (GTIG) for their collaboration on tracking the reemergence of this activity.

Microsoft Threat Intelligence has identified a cluster of compromised websites leading to ClickFix attacks. Instead of downloading and executing remote payloads like the typical attack pattern, in this attack, the websites pre-fetch a script payload into the browser cache disguised as a PNG file. When a user is later tricked into executing the malicious command, the cached website content is already on the device, loaded, and ready to be executed. This helps to hide the payload script and helps bypass the character limit of the Run dialog. ClickFix attacks persuade users to execute attacker-supplied commands under the guise of verification or repair. In this specific campaign, a fake lure instructs users to open Windows Run, paste clipboard content and press Enter. The injected page uses browser caching to stage the larger VBScript payload separately from the Run command. The command invokes cmd.exe to recursively enumerate files whose names start with "f_” in the browser’s profile folder such as %LOCALAPPDATA%\Mozilla\Firefox\Profiles. It compares each file’s byte length with an expected value. Rather than searching for a marker within the contents like previous attacks, it copies a size-matching cache entry to %LOCALAPPDATA%\Temp\t.vbs, giving the cached payload a VBScript extension, then executes it with wscript.exe. Copy output and errors are suppressed. The expected size varies across variants. The VBScript collects host information through WMI, retrieves v.ps1 from cocojambo[.]us[.]com/alfa, and launches PowerShell without a profile and with execution-policy bypass. A later PowerShell stage downloads the next-stage payload as cab.dat, then reads and executes its contents in a hidden window. The PowerShell stage triggers .NET compilation using csc.exe and cvtres.exe, then launches timeout.exe. Subsequent payloads load .NET assemblies into memory and inject code into timeout.exe to target browser and device credentials. The injected process launches PowerShell to retrieve another in-memory stage from capsysnet[.]vg and makes outbound connections to ciliabula[.]cc. The payload modifies the per-user PowerShell registry configuration to use the Bypass execution policy, then unpacks Python with tar.exe and creates a scheduled task that launches a Python payload through pythonw.exe for persistence. Microsoft Defender provides layered protection across the ClickFix attack chain. Defender SmartScreen and Defender for Office 365 help block malicious sites, links, attachments, and fake CAPTCHA lures, while Defender for Endpoint detects suspicious command execution and outbound connections through alerts like “Possible ClickFix activity”. Defender Antivirus blocks malicious command execution as Trojan:Win32/ClickFix and Trojan:Win32/TermFix. Microsoft recommends cloud-delivered, web, and network protection, application control, and PowerShell script-block logging. Hunt across browser activity, RunMRU registry key, WScript/PowerShell child processes and scheduled tasks, not download events alone. A CAPTCHA should not ask users to run code. Users shouln not paste commands from verification prompts into Run, Terminal or PowerShell and should treats such requests as potential initial access attempts.

The 2026 Microsoft Digital Defense Report is out today, examining a threat landscape increasingly defined by interdependence. Read the full report: msft.it/6018alHd6 Connections among identities, AI systems, cloud services, software supply chains, edge infrastructure, and critical systems can create points of leverage where one compromise has effects far beyond the initial target. AI is accelerating familiar threat actor tradecraft rather than replacing it. Identity compromise, credential reuse, social engineering, and exploitation remain prevalent, but automation enables adversaries to conduct these activities with greater speed and scale. In 52.2% of intrusions involving valid accounts, attackers pursued additional credential theft, creating opportunities for one compromised identity to fuel further unauthorized access. These operations leave signals across identities, endpoints, infrastructure, applications, cloud environments, email, and networks. Individually, those signals may provide only a partial view. When correlated with threat intelligence, they can reveal threat actor activity across campaigns, clarify how an intrusion is progressing, and surface risks that isolated investigations may miss. For defenders, success increasingly depends on connecting telemetry quickly enough to understand adversary operations and act before threats can escalate. Get more insights on this year’s report from Terrell Cox: msft.it/6017alHjh

Microsoft Threat Intelligence identified and tracked exploitation of CVE-2026-73570, an unauthenticated OS command injection vulnerability affecting internet-facing mail servers that enabled compromise without authentication or user interaction. msft.it/6015aYZ6L Successful exploitation led to webshell deployment, reverse shells, privilege escalation, persistent remote access tooling, and collection of authentication and mailbox data. Microsoft observed both automated payload delivery and hands-on-keyboard activity on compromised mail servers. Analysis of confirmed compromises revealed multiple attack paths and pre-disclosure reconnaissance activity targeting the same injection path before public disclosure. Read the full research for technical details, detection opportunities, and mitigation guidance.

Microsoft Defender Experts observed phishing campaigns targeting organizations across multiple industries that distributed legitimate RMM software via meeting invitations, PDF-themed lures, software update prompts, and other social engineering content. msft.it/6016acCYr After execution, the software established a remote management foothold and was used to deploy a second remote access platform, creating redundant access channels that supported persistent access and follow-on activity, including information collection and credential access operations. The activity highlights how threat actors continue to abuse legitimate administration tools to blend into normal IT operations while maintaining access and reducing detection opportunities. Read the full analysis for additional findings and guidance.

Since January 2026, Microsoft has observed Russian state actor Star Blizzard evolve their detection evasion capabilities via large-scale phishing campaigns, the use of accounts on compromised websites, and a new malware delivery technique called RedFlick. msft.it/6010actya RedFlick can enable CosmicPulse malware installation after a single user interaction, reducing friction in the compromise process. Combined with the actor’s updated tactics, techniques, and procedures (TTPs), these changes improve Star Blizzard’s ability to reach more targets and increase the likelihood of successful compromise These developments reflect the actor’s continued efforts to streamline malware deployment and scale operations to support ongoing cyberespionage objectives. Get detections, indicators of compromise (IOCs), and hunting guidance from this Microsoft Threat Intelligence blog post.

Microsoft Threat Intelligence identified NeedyMantis, a modular post-compromise malware family used in a limited number of targeted operations. Observed activity has aligned with activity Microsoft associates with threat actors operating from China. msft.it/6011acEgc NeedyMantis is typically deployed after access has already been established, suggesting it is used to maintain long-term access and support follow-on operations for selective intrusions rather than gain an initial foothold. The malware combines custom loaders, encrypted archives, and modular components that enable operators to evade analysis and extend functionality. Get detections, mitigation, IOCs, and hunting guidance from this Microsoft Threat Intelligence blog post.

Microsoft Security Research has identified extensive cloud resource destruction activity linked to JADEPUFFER, which Microsoft tracks as Storm-3168. The activity used compromised service principals and performed cloud credential collection that could be used to facilitate future exfiltration. msft.it/6015a9lob Two compromised service principals divided discovery, destruction, and credential collection, with timing and overlapping token streams strongly indicating automated or scripted execution that included more than 100 storage account deletion attempts in about seven minutes. Discovered by Sysdig in July 2026, JADEPUFFER is reported to be the first documented agentic ransomware operation. These new findings expand publicly documented activity associated with Storm-3168 and indicate an evolution in the threat actor's cloud operations. Read the blog for analysis, Microsoft Defender detections, and mitigation guidance on protecting workload identities, revoking or rotating exposed credentials, and safeguarding backup and recovery resources.

Across intrusions leading to different ransomware payloads, the ransomware affiliate Storm-2570 has used consistent post-compromise tools and techniques, highlighting the value of monitoring recurring attacker behaviors rather than tracking payloads alone. msft.it/6015a9GkD Storm-2570 has used largely uniform tradecraft, including remote access, credential theft, lateral movement, security tampering, and data exfiltration, across deployments involving Qilin, DragonForce, Anubis, and BERT ransomware. Read the latest Microsoft Threat Intelligence blog for a comprehensive analysis of Storm-2570 activity, as well as Microsoft Defender detections, hunting guidance, and relevant mitigation recommendations, including tamper protection, credential hygiene, and configuring automatic attack disruption.