{"id":"MAL-2026-12006","summary":"Malicious code in @jsimplify/errno (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (3fb95765882f33f9d81fcfd6fe88ba4c274421923511121b7e9413e77c1dc69d)\nThe package declares a `scripts.install` hook that spawns `bun index.js` detached and unref'd on `npm install`, and pulls in `bun` as a declared dependency to guarantee the alternate runtime is present. `index.js` decrypts a hardcoded hex ciphertext with AES-256-CBC using an embedded key and IV to reconstruct a remote URL, fetches that URL, and passes the response body directly to `eval()`. This is a lifecycle-time dropper that executes attacker-controlled code on the installer's machine with the privileges of the user running `npm install`, with the destination URL obfuscated behind AES so it cannot be read from the source. The package presents itself as an errno-code lookup library, copying the code, README, description, and author string (`Rod Vagg @rvagg`) of the legitimate `errno` package while pointing `repository.url` at a different GitHub account (`maxpsmith/node-errno`); the errno-lookup functionality is a cover for the install-time execution path and there is no legitimate reason for an errno lookup library to AES-decrypt and eval remote content at install.\n\n## Source: ghsa-malware (01108c51624294a5a562a938781a1a19776b21b0055836bdcf70404a5cb63ab2)\nAny 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.\n","aliases":["GHSA-vgg6-7x38-g434"],"modified":"2026-08-05T10:05:25.672377330Z","published":"2026-08-04T17:39:09Z","database_specific":{"malicious-packages-origins":[{"source":"ghsa-malware","id":"GHSA-vgg6-7x38-g434","import_time":"2026-08-05T00:10:18.251382008Z","modified_time":"2026-08-04T17:40:14Z","ranges":[{"events":[{"introduced":"0"}],"type":"SEMVER"}],"sha256":"01108c51624294a5a562a938781a1a19776b21b0055836bdcf70404a5cb63ab2"},{"source":"amazon-inspector","versions":["2.0.7"],"id":"IN-MAL-2026-013393","import_time":"2026-08-05T07:06:45.248679486Z","modified_time":"2026-08-05T06:16:41Z","sha256":"3fb95765882f33f9d81fcfd6fe88ba4c274421923511121b7e9413e77c1dc69d"},{"modified_time":"2026-08-05T06:26:38Z","sha256":"cb5edb2ed2f73dbf304a1dc5118c072e38f4250fcdec46635dd1a3136cc761d5","source":"amazon-inspector","versions":["2.0.6"],"id":"IN-MAL-2026-013461","import_time":"2026-08-05T07:06:48.63319383Z"},{"source":"amazon-inspector","versions":["2.0.8"],"id":"IN-MAL-2026-013463","import_time":"2026-08-05T07:06:48.696669715Z","modified_time":"2026-08-05T06:26:56Z","sha256":"ef75d54a01a0ec11989eb4b609415b71195cd17ff771956e42808140ac4a476e"},{"sha256":"07ac81d802bf1fc5b384093fa9081c0bee6a7b4dc9e00697cfed9b7ec83ffe35","source":"amazon-inspector","versions":["2.0.5"],"id":"IN-MAL-2026-014283","import_time":"2026-08-05T09:27:51.451848146Z","modified_time":"2026-08-05T08:27:53Z"},{"id":"IN-MAL-2026-014252","import_time":"2026-08-05T09:27:47.893049961Z","modified_time":"2026-08-05T08:23:22Z","sha256":"2dde2d026cb9a167c3aed437299ba8e4ff451ed0e29ceafc2e646c2d5573ff2d","source":"amazon-inspector","versions":["2.0.1"]},{"source":"amazon-inspector","versions":["2.0.0"],"id":"IN-MAL-2026-014253","import_time":"2026-08-05T09:27:48.029493546Z","modified_time":"2026-08-05T08:23:31Z","sha256":"f6809f11168e39fbe844983dd1abe6524d589fad90b4c19e85faa9064bc2b948"}]},"references":[{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-vgg6-7x38-g434"},{"type":"PACKAGE","url":"https://www.npmjs.com/package/@jsimplify/errno/v/2.0.7"},{"type":"PACKAGE","url":"https://www.npmjs.com/package/@jsimplify/errno/v/2.0.6"},{"type":"PACKAGE","url":"https://www.npmjs.com/package/@jsimplify/errno/v/2.0.8"},{"type":"PACKAGE","url":"https://www.npmjs.com/package/@jsimplify/errno/v/2.0.5"},{"type":"PACKAGE","url":"https://www.npmjs.com/package/@jsimplify/errno/v/2.0.1"},{"type":"PACKAGE","url":"https://www.npmjs.com/package/@jsimplify/errno/v/2.0.0"}],"affected":[{"package":{"name":"@jsimplify/errno","ecosystem":"npm","purl":"pkg:npm/%40jsimplify/errno"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"}]}],"versions":["2.0.7","2.0.6","2.0.8","2.0.5","2.0.1","2.0.0"],"database_specific":{"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/@jsimplify/errno/MAL-2026-12006.json","cwes":[{"cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature.","name":"Embedded Malicious Code"},{"description":"The product contains code that appears to be malicious in nature.","name":"Embedded Malicious Code","cweId":"CWE-506"},{"cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature.","name":"Embedded Malicious Code"},{"name":"Embedded Malicious Code","cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature."},{"name":"Embedded Malicious Code","cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature."},{"cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature.","name":"Embedded Malicious Code"},{"name":"Embedded Malicious Code","cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature."}],"indicators":{"evidence_files":[{"path":"package.json","sha256":"d7ccd2df0334cb367079667d55f2e9f4cbfd63791907e69a531a25a1ad4f9b14","tlsh":"f8016825cca49eb326c86ad44cb90043ba615c0b8924fd18b6c3010d9b5d22f46fe7ee"},{"tlsh":"5e01819818feba2003b370fac6bb78cac070005e3189ddd0b35d8ea50fe1224490b68e","path":"index.js","sha256":"f012eb1c2812c51754f4a9046dd348c832192c1aef8258e1ec91fe7a5007b2fa"}]}}}],"schema_version":"1.8.0","credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"}]}