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2026-06-17 · 2026-Q2

Mastra AI npm Scope Compromise (Sapphire Sleet / UNC1069)

Outside the model: Adjacent ecosystemAgent tooling was not the attack surface, so no layer applies.

Fixable
Vendor patch
Vendor response
Unknown
In the wild
Yes
Actor
Not applicable

Target

144+ packages across the `mastra` and `@mastra` npm scope; `@mastra/core` draws more than 918,000 weekly downloads

Impact

The entire scope was backdoored in an 88-minute automated campaign; a malicious `easy-day-js` typosquat of dayjs ran a `postinstall` dropper that disabled TLS verification, contacted a C2, and downloaded a detached cross-platform information stealer that harvested browser history and 160+ cryptocurrency wallet extensions before self-deleting

Root cause

Takeover of a dormant former-contributor npm account (`ehindero`) that still held publish rights, reached via a malicious LinkedIn link to an active employee; Microsoft attributed it to North Korean actor Sapphire Sleet (UNC1069), the same actor behind the earlier Axios compromise

Sources

Catalog

Cite this: AgentProv incident record: Mastra AI npm Scope Compromise (Sapphire Sleet / UNC1069) (2026-06-17). https://agentprov.com/incidents/2026-06-17-mastra-ai-npm-scope-compromise-sapphire-sleet-unc1069