MAL-2026-13747

See a problem?
Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/base65-13x/MAL-2026-13747.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-13747
Aliases
  • GHSA-fp83-xcpx-v3qm
Published
2026-08-11T16:40:07Z
Modified
2026-08-12T00:30:12Z
Summary
Malicious code in base65-13x (npm)
Details

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

Source: amazon-inspector (59226f2c38efcc1dd5de6423edfc866125564cd726915307d7a05ca5b5f13529)

base65-13x@5.0.2 impersonates cryptocoinjs/base-x, reusing its README, homepage, and API surface, but the exported decode(string) function in both src/esm/index.js (line 114) and src/cjs/index.cjs (line 116) contains a ~123KB VM-style obfuscated payload using rotated identifiers (vmR, vmr_92f1a9, vmw_4ee781) built via Object.defineProperty. The blob contains multiple references to the Function constructor and fetch, indicating dynamic code construction and outbound network I/O. Genuine base-x is roughly 50 lines of pure arithmetic with no obfuscation and no network activity. Any consumer invoking decode() on this package executes the packed VM, which dynamically constructs code with fetch capability. The destination hosts and constructed code are concealed by the obfuscation and are not statically visible.

Source: ghsa-malware (8f16b7879f3a0b67bc7621645bf52c742af231c6e4156550ff4393f0167936ad)

Any 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.

Database specific 
{
    "malicious-packages-origins": [
        {
            "id": "IN-MAL-2026-017378",
            "import_time": "2026-08-11T18:52:00.018307592Z",
            "modified_time": "2026-08-11T18:48:44Z",
            "sha256": "59226f2c38efcc1dd5de6423edfc866125564cd726915307d7a05ca5b5f13529",
            "source": "amazon-inspector",
            "versions": [
                "5.0.2"
            ]
        },
        {
            "id": "GHSA-fp83-xcpx-v3qm",
            "import_time": "2026-08-12T00:17:04.863329038Z",
            "modified_time": "2026-08-11T16:40:08Z",
            "ranges": [
                {
                    "events": [
                        {
                            "introduced": "0"
                        }
                    ],
                    "type": "SEMVER"
                }
            ],
            "sha256": "8f16b7879f3a0b67bc7621645bf52c742af231c6e4156550ff4393f0167936ad",
            "source": "ghsa-malware"
        }
    ]
}
References
Credits

Affected packages

npm / base65-13x

Package

Name
base65-13x
View open source insights on deps.dev
Purl
pkg:npm/base65-13x

Affected ranges

Type
SEMVER
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

5.*
5.0.2

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": "src/cjs/index.cjs",
            "sha256": "c7a7bb51be241d19e36e6d10e9604d63466fa51d317c1622f7f8a42eec0f65de",
            "tlsh": "f3c3b651abd9f02940ef762085d7e332f901e8f245182d7cc3a1eb695f7264a85faf60"
        },
        {
            "path": "src/esm/index.js",
            "sha256": "6c1d816969f2e15d5bef248891c7482f6feaf6f90bc6d31ede384a4104783fcf",
            "tlsh": "51c3b651abd9f02940ef762085d7e332f901e8f245182d7cc3a1eb695f7264a85faf60"
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/base65-13x/MAL-2026-13747.json"