Malicious code in js-crypto-promise (npm)
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (a9d677e45bee46911d04564e9260f4b569119a4ca0a13a58bcd43760359fbb4f) The package's `prepinstall.js` script base64-decodes a hidden URL (stored in a constant misleadingly named `HASH_KEY` decoding to https://jsonkeeper.com/b/DWNFF, an anonymous paste service), fetches the JSON body via axios, reads the `.cache` field, and pipes the contents into a detached `node` child process via stdin: `const child = spawn('node', [], { detached: true, stdio: ['pipe', 'ignore', 'ignore'] }); child.stdin.write(k1);`. This dropper fires automatically on `npm install` via `scripts.postinstall`. To defeat the `--ignore-scripts` mitigation, `index.js` also wraps a dynamic `import('./prepinstall.js')` inside a top-level IIFE, so any consumer that `require('js-crypto-promise')` re-triggers the same remote fetch and execution. The payload host is mutable, anonymous, unpinned, and unverified — the package author can swap in arbitrary code at any time. The package name impersonates the legitimate `crypto-promise` package: the README copies the real package's example code and embeds the real package's npm badge link, and the homepage points at the legitimate maintainer's GitHub repo. Installer impact: any `npm install` or `require()` of this package executes attacker-controlled Node.js code on the installer's machine. ## Source: ghsa-malware (e9fe53199afdef1859ff9dc2c719ee2631c26ac984d1f8ed3387b10ea35b306e) 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.
AI Analysis
Technical Summary
The 'js-crypto-promise' npm package (version 1.0.1) includes a 'prepinstall.js' script that base64-decodes a hidden URL pointing to an anonymous paste service. During 'npm install', this script fetches JSON data containing a '.cache' field, which is piped into a detached Node.js child process, executing arbitrary code. Additionally, requiring the package triggers dynamic import of 'prepinstall.js', bypassing the '--ignore-scripts' flag. The remote payload host is unpinned and mutable, allowing the attacker to change the code executed at any time. The package name and README mimic a legitimate package to mislead users. This results in automatic execution of attacker-controlled code on the installer's machine.
Potential Impact
Any system that installs or requires 'js-crypto-promise' version 1.0.1 is vulnerable to arbitrary code execution by the attacker. This can lead to full system compromise, including unauthorized access to secrets and keys stored on the machine. Because the attacker can change the remote payload at any time, the risk persists as long as the package remains installed or used. Removal of the package does not guarantee elimination of all malicious artifacts or backdoors introduced.
Mitigation Recommendations
No official patch or fix is available for this malicious package. The recommended mitigation is to immediately remove 'js-crypto-promise' version 1.0.1 from all affected systems. All secrets and keys stored on compromised machines should be rotated from a secure, unaffected environment. Users should avoid installing or requiring this package and verify package authenticity before use. Monitor for any signs of compromise and consider full system remediation due to potential persistent control by attackers.
Malicious code in js-crypto-promise (npm)
Description
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (a9d677e45bee46911d04564e9260f4b569119a4ca0a13a58bcd43760359fbb4f) The package's `prepinstall.js` script base64-decodes a hidden URL (stored in a constant misleadingly named `HASH_KEY` decoding to https://jsonkeeper.com/b/DWNFF, an anonymous paste service), fetches the JSON body via axios, reads the `.cache` field, and pipes the contents into a detached `node` child process via stdin: `const child = spawn('node', [], { detached: true, stdio: ['pipe', 'ignore', 'ignore'] }); child.stdin.write(k1);`. This dropper fires automatically on `npm install` via `scripts.postinstall`. To defeat the `--ignore-scripts` mitigation, `index.js` also wraps a dynamic `import('./prepinstall.js')` inside a top-level IIFE, so any consumer that `require('js-crypto-promise')` re-triggers the same remote fetch and execution. The payload host is mutable, anonymous, unpinned, and unverified — the package author can swap in arbitrary code at any time. The package name impersonates the legitimate `crypto-promise` package: the README copies the real package's example code and embeds the real package's npm badge link, and the homepage points at the legitimate maintainer's GitHub repo. Installer impact: any `npm install` or `require()` of this package executes attacker-controlled Node.js code on the installer's machine. ## Source: ghsa-malware (e9fe53199afdef1859ff9dc2c719ee2631c26ac984d1f8ed3387b10ea35b306e) 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.
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The 'js-crypto-promise' npm package (version 1.0.1) includes a 'prepinstall.js' script that base64-decodes a hidden URL pointing to an anonymous paste service. During 'npm install', this script fetches JSON data containing a '.cache' field, which is piped into a detached Node.js child process, executing arbitrary code. Additionally, requiring the package triggers dynamic import of 'prepinstall.js', bypassing the '--ignore-scripts' flag. The remote payload host is unpinned and mutable, allowing the attacker to change the code executed at any time. The package name and README mimic a legitimate package to mislead users. This results in automatic execution of attacker-controlled code on the installer's machine.
Potential Impact
Any system that installs or requires 'js-crypto-promise' version 1.0.1 is vulnerable to arbitrary code execution by the attacker. This can lead to full system compromise, including unauthorized access to secrets and keys stored on the machine. Because the attacker can change the remote payload at any time, the risk persists as long as the package remains installed or used. Removal of the package does not guarantee elimination of all malicious artifacts or backdoors introduced.
Mitigation Recommendations
No official patch or fix is available for this malicious package. The recommended mitigation is to immediately remove 'js-crypto-promise' version 1.0.1 from all affected systems. All secrets and keys stored on compromised machines should be rotated from a secure, unaffected environment. Users should avoid installing or requiring this package and verify package authenticity before use. Monitor for any signs of compromise and consider full system remediation due to potential persistent control by attackers.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- MAL-2026-5569
- Osv Schema Version
- 1.7.4
- Aliases
- ["GHSA-hj2h-j6cr-5mq8"]
- Ecosystems
- ["npm"]
- Database Specific Severity
- null
- Cvss Version
- null
Threat ID: 6a4c341527e9c797195f7ef9
Added to database: 07/06/2026, 23:02:45 UTC
Last enriched: 07/06/2026, 23:18:53 UTC
Last updated: 07/31/2026, 14:50:07 UTC
Views: 17
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