A framework crossing between state programmes
Microsoft Threat Intelligence reported on 29 October that two North Korean groups it tracks as Onyx Sleet and Pearl Sleet have, since late October, used ARTEX, an open-source agentic penetration testing framework, in live operations.
That is the second state-linked programme tied to the same tool in a week. CrowdStrike reported in late October that a China-nexus group it calls VAPOR PANDA had used ARTEX to scale a campaign against more than 200 organisations. The framework is public, so adoption across unrelated programmes is what one would expect — and it is also why a defence tuned to one group’s use of it is unlikely to hold.
Four tiers, and nobody in the bottom one
Microsoft rates overall North Korean AI adoption as “high” and sorts the groups it tracks into four stages. Jade Sleet, Coral Sleet and Jasper Sleet are “operationalized”. Diamond Sleet, Onyx Sleet, Pearl Sleet and Sapphire Sleet are “accelerating”. Emerald Sleet is “expanding”. No group is assessed as merely “emerging”.
The qualifier is the part worth keeping. Microsoft says these operations remain “human-directed and have not become fully autonomous”, and that AI is mainly enhancing existing tradecraft and operator productivity rather than replacing the operator.
What the volume looks like
The clearest evidence of scale is document generation. Microsoft says it identified more than 100 PDF lure files carrying target-specific detail, created in August and September 2026, with dozens produced within minutes of each other — a pattern it attributes to an AI platform. They supported phishing aimed at South Korean targets.
Other findings are about workflow rather than volume. Coral Sleet has run a pipeline since April 2026 that trojanises private GitHub repositories and folds them into its malware chain, which Microsoft says was highly likely built with an AI-enabled development platform. Sapphire Sleet is assessed as having probably used AI during an August 2026 compromise of Rust software, with dynamic .NET compilation after exploitation. Jade Sleet, Coral Sleet, Pearl Sleet and Sapphire Sleet are all judged likely users of the AI coding tool Cursor for writing, debugging and retooling after defenders act.
The personas and the targets
Two shifts sit alongside the tooling. Between 8 and 12 June 2026, Jade Sleet ran job-themed targeting through three front companies, posing as recruiters for a spoofed blockchain intelligence firm that advertised itself as AI-powered. And Diamond Sleet has returned to the oil and gas sector since August 2026, for the first time since 2023, while also creating fake communications technology companies to approach telecom firms.
Jasper Sleet, the group associated with North Korea’s remote IT worker schemes, is described as using AI-assisted résumé workflows and repeatable tooling to run its fake personas.
What to watch
Microsoft’s own framing is that none of this is new in kind — it published a report on North Korean AI tradecraft in March 2026 — and that the change is in degree and in tooling. The thing to watch is ARTEX. An agentic framework that two unrelated state programmes picked up within weeks of each other is a defensive problem that does not belong to either of them.
