Which versions of signup-embedder are malicious?

The following npm versions of signup-embedder are flagged malicious: 99.99.99-poc2, 99.99.99-poc3. Treat any of these as compromised.

How do I remediate signup-embedder if I installed it?

signup-embedder is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.

I already installed signup-embedder — how do I know if it already compromised me?

If signup-embedder was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.

Is signup-embedder part of a known attack campaign?

Yes — signup-embedder is associated with the IN-MAL-2026-007435, IN-MAL-2026-007450, GHSA-8j4q-hx83-pfq9 campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

How do I find signup-embedder across my projects, lockfiles, and CI pipelines?

Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for signup-embedder (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging signup-embedder across your stack and pipelines.

Malicious package

signup-embeddernpm

Malicious code in signup-embedder (npm) Remove it immediately and rotate any exposed credentials.

MAL-2026-6396

Immediate action

Remove the package, then rotate any secrets the build/runtime could reach.

npm uninstall signup-embedder

What this malware does

[email protected] ships preinstall.js and postinstall.js lifecycle scripts that auto-execute on npm install. preinstall.js collects hostname, current working directory, pid, Node version, platform/arch, user, and the list of environment variable names, and POSTs them as JSON to https://webhook.site/f83b073c-a04a-4ac5-8930-507051bd22f7; it also performs a DNS lookup against <timestamp>.callbacks.report for out-of-band confirmation. postinstall.js POSTs a similar host fingerprint (host, cwd, pid, node, platform) to the same webhook.site URL. The package's own description and comments label it a 'HubSpot dependency confusion PoC', and the 99.99.99-poc2 version is the canonical high-version shape used to win resolution against an internal package of the same name. Regardless of the 'PoC' framing, the package is published on the public npm registry and any installer (CI, developer machine, internal build) that resolves the name will have its host identifiers and environment variable names beaconed to an attacker-controlled collector and DNS sink, enabling internal-network mapping and follow-on targeting.

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

2 flagged

99.99.99-poc299.99.99-poc3

Indicators of compromise (SHA-256)

c48f398f700b78d1893db4570d5d6f16985d937ee79677aab97e673a1cf86e7e

40e099c9ff8cac8636bf152cfd90311c15fc38418e8095f813f06cd97f339b1a

8595830013c2298b23fd077af3a2e8ce9722520fdfff68d04ef8135ce11173ca

Detection & response playbook

Credential / info stealer

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for signup-embedder (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging signup-embedder across your stack and pipelines.
If you installed it — respond
signup-embedder is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If signup-embedder was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks signup-embedder before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.

Frequently asked questions

No. signup-embedder on npm has been identified as a malicious package (versions 99.99.99-poc2, 99.99.99-poc3 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-007435IN-MAL-2026-007450GHSA-8j4q-hx83-pfq9

References

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks signup-embedder-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.

Malware detection Runtime egress monitoring