Microsoft Details North Korean Threat Actors’ Expanding Use of AI
Summary
Microsoft Threat Intelligence reports that North Korean actors use AI to scale targeting, social engineering, tool development, and operations. Microsoft assesses the activity remains human-directed and provides mitigation guidance and Defender detections.
Key points
- Microsoft assesses Jade Sleet, Coral Sleet, and Jasper Sleet have operationalized AI across their workflows; other tracked actors are at accelerating or expanding stages.
- Microsoft attributes more than 100 target-specific PDF lures created by Onyx Sleet in August and September 2026 to the actor, assessing they were highly likely generated rapidly with AI.
- Microsoft says Jade Sleet used AI-assisted workflows to accelerate job-themed targeting across multiple front companies in June 2026.
- Microsoft identified evidence that Coral Sleet uses a workflow to trojanize private GitHub repositories and that Sapphire Sleet likely used AI during an August 2026 Rust software compromise.
- Microsoft observed Onyx Sleet and Pearl Sleet using the open-source agentic AI penetration-testing framework ARTEX in operations since late October 2026.
- Microsoft assesses these operations remain human-directed, and recommends defenses including phishing protections, employee vetting, vulnerability management, and endpoint protections.
Article Details
- Event Type
- Microsoft Threat Intelligence report on North Korean threat actors adopting AI across cyber operations.
- Impact
- Microsoft Threat Intelligence assesses that AI is helping these actors accelerate reconnaissance, tailored social engineering, persona creation, malware and tooling development, and operational scaling. Reported activity includes high-volume phishing and the trojanization of private GitHub repositories, increasing the speed and scale of threats to targeted organizations. Microsoft assesses that these operations remain human-directed and are not fully autonomous.
Threat Actors
Coral SleetMicrosoft Threat Intelligence reports that Coral Sleet operationalized a workflow to trojanize private GitHub repositories and integrate them into its malware chain, assessing that an AI-enabled development platform highly likely helped engineer the capability.Diamond SleetMicrosoft Threat Intelligence reports that Diamond Sleet returned to targeting the oil and gas sector in August 2026, also targeting communications, internet policy, and defense-related organizations. It reports fake communications technology companies and assesses that AI may improve reconnaissance and technical development.Jade SleetMicrosoft Threat Intelligence reports job-themed targeting using tailored domains, social media profiles, and three front companies in a short period in June 2026. It assesses that generative AI helped accelerate target-specific research and outreach.Jasper SleetMicrosoft Threat Intelligence reports that Jasper Sleet uses fraudulent identities and suspected generative and agentic AI-assisted resume workflows to support employment-themed operations. It also reports AI-assisted management of multiple fraudulent worker personas.KimsukyMicrosoft Threat Intelligence reports possible AI-created voice and video media by Emerald Sleet, while stating it has not determined the full operational impact. It assesses Emerald Sleet's AI adoption as expanding.Onyx SleetMicrosoft Threat Intelligence attributes more than 100 target-specific PDF lures created in August and September 2026 to Onyx Sleet, assessing that AI likely enabled their rapid production. It also reports that Onyx Sleet leveraged ARTEX in operations since late October 2026.Pearl SleetMicrosoft Threat Intelligence reports that Pearl Sleet leveraged the open-source agentic AI penetration testing framework ARTEX in operations since late October 2026. It also identifies Pearl Sleet among actors likely using AI-assisted software development.Sapphire SleetMicrosoft Threat Intelligence reports that Sapphire Sleet conducted supply chain attacks and likely incorporated AI during the August 2026 Rust software compromise. The campaign involved malware development and deployment; Microsoft says the malware used dynamic .NET compilation during post-exploitation, most likely for defense evasion.
Malware
Vendors
Products
CursorThese tools include AI-assisted development platforms, such as Cursor, which have likely enabled Jade Sleet, Coral Sleet, Pearl Sleet, and Sapphire Sleet to:GitHubAnd, since April 2026, Coral Sleet has operationalized a workflow to trojanize private GitHub repositories, integrating them into their existing malware chain.Microsoft Agent 365Additionally, Microsoft Agent 365 serves as a control plane for AI agents in enterprise environments, allowing users to manage, govern, and secure AI agents and workflows while monitoring emerging risks of agentic AIMicrosoft Defender Antimalware PlatformMicrosoft Defender detectionsMicrosoft Defender for EndpointRun endpoint detection and response (EDR) in block mode so that Microsoft Defender for Endpoint can block malicious artifacts, even when your non-Microsoft antivirus does not detect the threat or when Microsoft DefenderMicrosoft Defender XDRConfigure automatic attack disruption in Microsoft Defender XDR.Microsoft EntraThe dashboard provides users with a unified view of AI security posture by aggregating security, identity, and data risk across Microsoft Defender, Microsoft Entra, and Microsoft Purview.Microsoft PurviewThe dashboard provides users with a unified view of AI security posture by aggregating security, identity, and data risk across Microsoft Defender, Microsoft Entra, and Microsoft Purview.Microsoft Security CopilotMicrosoft Security Copilot is embedded in Microsoft Defender and provides security teams with AI-powered capabilities to summarize incidents, analyze files and scripts, summarize identities, use guided responses, andMicrosoft Security Dashboard for AITo learn more about the Microsoft Security Dashboard for AI see: Assess your organization’s AI risk with Microsoft Security Dashboard for AI.
Tools
Industries
communicationsreturning to targeting the oil and gas sector for the first time since 2023, expanding their focus on communications and internet policy-related organizations, and continuing to target defense-related organizations.CryptocurrencyThese operations commonly target cryptocurrency and financial organizations, information technology companies and software supply chains, government entities, and education-related organizations.Defensetheir focus on communications and internet policy-related organizations, and continuing to target defense-related organizations.EducationThese operations commonly target cryptocurrency and financial organizations, information technology companies and software supply chains, government entities, and education-related organizations.financialThese operations commonly target cryptocurrency and financial organizations, information technology companies and software supply chains, government entities, and education-related organizations.GovernmentThese operations commonly target cryptocurrency and financial organizations, information technology companies and software supply chains, government entities, and education-related organizations.Information TechnologyThese operations commonly target cryptocurrency and financial organizations, information technology companies and software supply chains, government entities, and education-related organizations.Oil and gasSince August 2026, Microsoft Threat Intelligence has observed Diamond Sleet returning to targeting the oil and gas sector for the first time since 2023, expanding their focus on communications and internetSoftwareAI-assisted software and tooling developmentTelecommunicationstechnology companies, complete with supporting websites and tailored personas, to target telecommunications companies under the guise of legitimate business partnerships.