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Malicious package

sextant-relay-darwin-arm64npm

Advisory published Updated

sextant-relay-darwin-arm64 is a confirmed malicious npm package (MAL-2026-12193) that executes malicious code on install (malicious version 0.0.1-rc1). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in sextant-relay-darwin-arm64 (npm)

MAL-2026-12193
Immediate action
Remove the package, then rotate any secrets the build/runtime could reach.
npm uninstall sextant-relay-darwin-arm64

What this malware does

The tarball contains a single darwin/arm64 Mach-O Go executable at bin/sextant-relay (~6 MB, stripped) and a minimal package.json with no scripts, main, or bin entry — the package is designed to be selected as a platform-specific optional dependency of a parent package and invoked from there. The binary belongs to project github.com/ddos798/claude_control (referenced from package.json's license field) and its symbol table imports github.com/coder/websocket alongside a handleAgent routine and pseudo-terminal primitives (pty allocation, reader/writer state paired with WebSocket connection state). Together these produce a WebSocket-to-PTY relay: bytes arriving from a remote WebSocket peer are written into a local pty, and pty output is returned over the same socket, giving the operator of the WebSocket server interactive shell control on the host that runs the binary. The package name and description present the binary as a benign 'relay', which does not match its actual behavior. No install-time or import-time execution fires from this sub-package alone; the harm is realized when the parent package invokes the binary on a matching darwin/arm64 host.

Malicious versions

1 flagged
0.0.1-rc1

Indicators of compromise (SHA-256)

43407b6c2131e12ca9f2b18ee48505dbf7541e67aca1b94ad4fdc41e9fbca7c0

Detection & response playbook

Malicious package
  1. Find it

    Search your lockfiles and build artifacts for sextant-relay-darwin-arm64 (version 0.0.1-rc1).

  2. If you installed it — respond

    Remove sextant-relay-darwin-arm64 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.

  3. Did it already run?

    If sextant-relay-darwin-arm64 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

No. sextant-relay-darwin-arm64 on npm has been identified as a malicious package (version 0.0.1-rc1 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-014374

References

Credits

  • Amazon Inspector · finder

Detect & block this

O3 blocks sextant-relay-darwin-arm64-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.

Explore

sextant-relay-darwin-arm64 (npm) malicious package — MAL-2026-12193 | O3 Security