mfaby

{"modified":"2026-09-09T21:10:42Z","published":"2026-09-09T21:10:42Z","schema_version":"1.7.4","id":"MAL-2026-16101","summary":"Malicious code in mfaby (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (c278e0ee3820cf701ef7ad65dfdab43a0765e5d3423286de99d3301fe39a8455)\nThe package presents itself as a Discord MFA helper, but its cache module contains a _warmSession routine that decodes a base64-encoded string (_CDN_BASE) into the URL https://limbomail.com/api/attachment/l4TIRPOsaUxR._603-vhKDRdgKl3RalN_TVUZYGPsJy2Y, downloads the response body, writes it to a file in os.tmpdir(), and executes it via new Worker(tmp). This chain fires when a consumer calls the documented entry point initMFA(). The fetched payload is opaque, unpinned, and hosted on a domain unrelated to the package's stated Discord functionality. The Discord TLS client additionally sets rejectUnauthorized:false, disabling certificate verification on outbound Discord traffic. The base64 concealment of the drop URL combined with a README cover-story describing it as a 'runtime patch asset' indicates deliberate hiding of the endpoint.\n","affected":[{"package":{"ecosystem":"npm","name":"mfaby"},"versions":["1.0.0"],"database_specific":{"cwes":[{"cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature.","name":"Embedded Malicious Code"}],"indicators":{"evidence_files":[{"path":"lib/http.js","sha256":"662e532b1dbda17dc95ceadb7f8eecdcd020bdc66d638bac17c30ee2464f4330","tlsh":"c8b1439a24f2706946fbd5ec9327e86af3779103714dd9a0f21c82b11f8256c8b665c8"},{"path":"index.js","sha256":"52583b62314f049289a83dfe59ef488e587deea24c45a783a099b953f7631698","tlsh":"a412621121f7203a0363d0ff9bd7d01567345903355ae9b8b78c9684afc361a85b3aee"}],"package_integrity":[{"filename":"mfaby-1.0.0.tgz","hashes":{"sha1":"f91b1881c1b7059456aa977fc350a83120a1e241","sha512_sri":"sha512-xMFK9+e5hqBwrhHtHX65EFWUMse8lqoERkgtx4ppwSYIePMcWbWix6sMb4p+YM36DUXO9pnNE+Hwsy2zcOtKRw=="}}]}}}],"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/mfaby/v/1.0.0"}],"credits":[{"name":"Amazon Inspector","type":"FINDER","contact":["inspector-research@amazon.com"]}],"database_specific":{"malicious-packages-origins":[{"id":"IN-MAL-2026-019900","import_time":"2026-09-09T21:14:32.927492477Z","modified_time":"2026-09-09T21:10:42Z","sha256":"c278e0ee3820cf701ef7ad65dfdab43a0765e5d3423286de99d3301fe39a8455","source":"amazon-inspector","versions":["1.0.0"]}]}}