Case mastra-npm-sapphire-sleetAI supply chainWorldwide
North Korea's Sapphire Sleet hijacks maintainer account to trojanize 140+ Mastra AI npm packages
Attackers took over npm maintainer 'ehindero' and pushed updates to more than 140 @mastra packages adding the typosquat dependency easy-day-js, whose postinstall dropper fetched a cross-platform infostealer hunting 166 wallet extensions.
CriticalAttack on AIStatus: ContainedVerified case file
Open in the interactive mapCite this case
- Reported
- Jun 17, 2026
- Location
- Worldwide
- Target
- Developers using the @mastra AI agent framework
- Severity
- Critical
- Triggered by
- Sapphire Sleet (BlueNoroff)
- Actor type
- State-sponsored
- Reported loss
- None reported
- CVE
- None
What happened
Attackers took over npm maintainer 'ehindero' and pushed updates to more than 140 @mastra packages adding the typosquat dependency easy-day-js, whose postinstall dropper fetched a cross-platform infostealer hunting 166 wallet extensions.
Impact: More than 140 packages poisoned; stealer collected host details, browser histories and wallet extension data on Windows, macOS and Linux with persistence; victim count not disclosed
Who triggered it
Actor: Sapphire Sleet (BlueNoroff)
Attribution: Microsoft assessed with high confidence that the PowerShell backdoor, tradecraft and C2 infrastructure match Sapphire Sleet, a North Korean actor also behind the April 2026 Axios npm attack
Motive: Theft of credentials, API keys, tokens and cryptocurrency wallets for revenue generation
How it happened
Attack vector: Hijacked maintainer account publishing malicious versions; postinstall hook disabled TLS verification and ran an obfuscated dropper that launched a hidden second-stage stealer
Root cause: Single maintainer account with publish rights across the whole package scope and no additional release protections
Timeline
- Microsoft discloses the Mastra npm compromise
- Microsoft update attributes the activity to Sapphire Sleet
- BleepingComputer reports follow-on PowerShell backdoors and SYSTEM-level services on contacted hosts
Response
Microsoft published analysis and attribution; remediation by npm and Mastra not detailed in reporting
Current status: Contained
Sources (open in a new tab)
- BleepingComputer bleepingcomputer.com
- BleepingComputer npm tag bleepingcomputer.com
Cite this case
North Korea's Sapphire Sleet hijacks maintainer account to trojanize 140+ Mastra AI npm packages. AI Threat Watch, case mastra-npm-sapphire-sleet, Jun 17, 2026. https://aithreat.io/cases/mastra-npm-sapphire-sleet/
Permanent link: https://aithreat.io/cases/mastra-npm-sapphire-sleet/