eventea-diagnpm
Advisory published Updated
eventea-diag is a confirmed malicious npm package (MAL-2026-12373) that executes malicious code on install (malicious version 20.5.3). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in eventea-diag (npm)
What this malware does
On require of the package, index.js loads shim.js which downloads a platform-specific binary from hardcoded Cloudflare Workers subdomains (oob-worker.cf102-baf.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf99-9b3.workers.dev) with a DNS-TXT base64 fallback to dl.well1.site, writes the bytes to a hidden temp file, chmods 755, and spawns it detached via /bin/sh -c or cmd. Host strings and dangerous APIs are assembled from split fragments at runtime (e.g. ["oob-worker.cf102-baf",".w","or","ke","rs",".d","ev"].join(""), require("child"+"process"), fs["chmod"+"Sync"]) to hide the destinations and primitives from static analysis. Cover-story naming (analytics_state, dotnet_diag_.exe,.cache_) does not match the package's stated pub/sub adapter purpose. A second dropper implementation with the same pattern is bundled as lib/telemetry.js (81KB) framed as an 'Analytics SDK'. There is no pinning, no signature verification, and the delivery hosts are anonymous Cloudflare Workers subdomains unrelated to any declared publisher.
Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for eventea-diag (version 20.5.3).
If you installed it — respond
Remove eventea-diag from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If eventea-diag was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks eventea-diag-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.