Which versions of crypto-promiser are malicious?

The following npm versions of crypto-promiser are flagged malicious: 1.0.1. Treat any of these as compromised.

How do I remediate crypto-promiser if I installed it?

crypto-promiser establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.

I already installed crypto-promiser — how do I know if it already compromised me?

If crypto-promiser 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 crypto-promiser part of a known attack campaign?

Yes — crypto-promiser is associated with the IN-MAL-2026-008174 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 crypto-promiser 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 crypto-promiser (version 1.0.1). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging crypto-promiser across your stack and pipelines.

Malicious package

crypto-promisernpm

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

MAL-2026-7010

Immediate action

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

npm uninstall crypto-promiser

What this malware does

[email protected] is a typosquat of the legitimate crypto-promise package that ships a dropper in its lifecycle scripts. The declared postinstall runs prepinstall.js, which decodes a base64-hidden URL (aHR0cHM6Ly9qc29ua2VlcGVyLmNvbS9iL1dEVDFI -> https://jsonkeeper.com/b/WDT1H) via atob, fetches JSON from that anonymous paste host with axios, and pipes the .cache field of the response into a detached node child process over stdin, executing attacker-controlled JavaScript on npm install. index.js also contains a top-level IIFE that dynamically imports./prepinstall.js, causing the same fetch-and-exec to fire when the package is require()d or imported. The package name is a single-character edit of crypto-promise and mirrors its API surface (hash, hmac, cipher, pbkdf2) as a lure. The remote payload host is anonymous and mutable, the destination is obfuscated behind base64, and executed bytes come from a non-registry third-party paste — arbitrary code execution on the installer machine at install time and at require time.

Malicious versions

1 flagged

1.0.1

Indicators of compromise (SHA-256)

25594e7865a7525aebefd2f1fcc8060f144bf202b1986875e1cfd95564f66e88

Detection & response playbook

Backdoor / remote access

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for crypto-promiser (version 1.0.1). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging crypto-promiser across your stack and pipelines.
If you installed it — respond
crypto-promiser establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.
Did it already run?
If crypto-promiser 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 crypto-promiser 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. crypto-promiser on npm has been identified as a malicious package (version 1.0.1 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-008174

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks crypto-promiser-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.

Malware detection Runtime egress monitoring