Which versions of supersig are malicious?

The following npm versions of supersig are flagged malicious: 1.0.5. Treat any of these as compromised.

How do I remediate supersig if I installed it?

supersig 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 supersig — how do I know if it already compromised me?

If supersig 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 supersig part of a known attack campaign?

Yes — supersig is associated with the IN-MAL-2026-016813 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 supersig 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 supersig (version 1.0.5). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging supersig across your stack and pipelines.

Malicious package

supersignpm

supersig is a confirmed malicious npm package (MAL-2026-13461) that steals credentials and exfiltrates sensitive data (malicious version 1.0.5). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in supersig (npm)

MAL-2026-13461

Immediate action

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

npm uninstall supersig

What this malware does

The published dist bundles (dist/supersig.cjs.js, dist/supersig.esm.js, dist/supersig.umd.js), reached via the package's main/module/browser entries on require/import, contain a decrypt-and-execute chain that is absent from the src/ tree. The bundles import a DES key from an unpinned dependency mkb-manager@latest, call decryptToken on an embedded encrypted token to produce plaintext code, spawn a fresh node child process via child_process.spawn('node', [],...), and write the decrypted bytes into that process's stdin (rsa_exec.stdin.write / des_exec.stdin.write). Any consumer that requires or imports this package executes the decrypted payload at load time. Because mkb-manager is pinned to latest, whoever controls that package can rotate the decryption key/payload at will, making the executed code opaque and mutable. The src/ wallet, signers, providers, and transactions modules contain no decryptToken, readRSAFromPackage, mkb-manager, or child_process usage — the dropper is present only in the shipped bundles, indicating deliberate concealment from source-tree review.

Malicious versions

1 flagged

1.0.5

Indicators of compromise (SHA-256)

557f8e62aa65bb4fe5e96a52cf6c5ba83c2f1bcf47eca3027bf4daca071249e5

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 supersig (version 1.0.5). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging supersig across your stack and pipelines.
If you installed it — respond
supersig 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 supersig 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 supersig 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. supersig on npm has been identified as a malicious package (version 1.0.5 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-016813

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks supersig-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

Explore

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