fmt-util-k7x2

{"schema_version":"1.7.4","id":"MAL-2026-13950","published":"2026-08-13T17:20:45Z","modified":"2026-08-13T21:22:58.996963326Z","summary":"Malicious code in fmt-util-k7x2 (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (0e8613ffc5393a31685344c247925a5ef104f7daf3f0d2f45a51918adba7d344)\nfmt-util-k7x2@1.0.1 advertises itself as a trivial string-formatting utility (index.js exports two-line pad/trim helpers), but its package.json declares a postinstall hook that runs setup.js on every npm install. setup.js probes a list of Twilio-internal hostnames (including code.hq.twilio.com, stage.twilio.com, twilio.jfrog.io, artifacts.twilio.com) and the AWS EC2 instance metadata endpoint at 169.254.169.254, then concatenates the per-target reachability results and sends them as a query string to a hardcoded external host at http://whstool.brkd.no/cb53e6db-e043-4383-89e9-853c9088ee5d?v=<results>. The per-install UUID callback identifies each victim uniquely, and the target set (internal corporate hostnames + cloud metadata service) matches the dependency-confusion reconnaissance pattern. The exfil destination is not owned by Twilio and is unrelated to the package's advertised purpose. The random-suffix name and mismatch between advertised functionality and postinstall behavior are consistent with a targeted dependency-confusion package aimed at Twilio build environments.\n","affected":[{"package":{"name":"fmt-util-k7x2","ecosystem":"npm"},"versions":["1.0.1","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"},{"cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature.","name":"Embedded Malicious Code"}],"indicators":{"evidence_files":[{"path":"setup.js","sha256":"d543daee38bd6a69538e80f0cde5f4b4b81e2b2cd9ec84709b1b48be553efe3b","tlsh":"da11effb01f0a05d0fd4cf98f61ada5fa523e605e080ca54f1d516304dc717a9bb02d8"}],"package_integrity":[{"filename":"fmt-util-k7x2-1.0.1.tgz","hashes":{"sha1":"604951d33fa14c01da8e1c8bb85dd2ff73e149ed","sha512_sri":"sha512-9DTm4GsmZk2I4O+rTuZ2fZRd12CU0BgDyix1AJD3ol3+boJ5QUvGVAKtVP7P6K+0S6ggzkWqzSLXaZbpvvSfXQ=="}}]}}}],"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/fmt-util-k7x2/v/1.0.1"},{"type":"PACKAGE","url":"https://www.npmjs.com/package/fmt-util-k7x2/v/1.0.0"}],"database_specific":{"malicious-packages-origins":[{"id":"IN-MAL-2026-017650","import_time":"2026-08-13T17:24:45.966714677Z","modified_time":"2026-08-13T17:20:45Z","sha256":"0e8613ffc5393a31685344c247925a5ef104f7daf3f0d2f45a51918adba7d344","source":"amazon-inspector","versions":["1.0.1"]},{"id":"IN-MAL-2026-017703","import_time":"2026-08-13T21:20:58.361715226Z","modified_time":"2026-08-13T21:11:23Z","sha256":"199c023d423783cbd5a697b3939d632b52e70029b86e59b63a69f4f298d39364","source":"amazon-inspector","versions":["1.0.0"]}]},"credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"}]}