MAL-2026-5579

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/webpack-cache-cycle/MAL-2026-5579.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-5579
Aliases
  • GHSA-2p34-5qgm-wr3f
Published
2026-06-11T05:06:33Z
Modified
2026-07-15T05:20:18Z
Summary
Malicious code in webpack-cache-cycle (npm)
Details

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

Source: amazon-inspector (82fa37e2478a7109e376e3a062ccb203806511033930eb7390e45fe7ef404b81)

On npm install, package.json's postinstall hook runs node -e "require('./loader.js')". loader.js spawns a detached node process that decodes a hex-encoded URL (https://jsonkeeper.com/b/L435A — an anonymous, mutable paste host), performs an HTTPS GET, writes the response's session field to a temporary.js file, and require()s it — executing attacker-controlled JavaScript on the installer's machine. The URL is obfuscated as a hex literal padded with whitespace inside Buffer.from(...) to evade naive string scanners. The detached spawn lets npm install exit cleanly while the dropper continues asynchronously. The package's advertised purpose is a webpack cache plugin, which does not justify any network access at install time. The package name webpack-cache-cycle and README title webpack-cache-plugin impersonate legitimate webpack tooling, with placeholder author metadata (Webpack Tools) and a non-existent GitHub repository.

Source: ghsa-malware (1a7e46df199f0d8dbede5404aab0ad253bb78bce77001d4b875d116806d9839d)

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-2026-005548",
            "import_time": "2026-06-11T05:41:05.871577895Z",
            "modified_time": "2026-06-11T05:06:34Z",
            "sha256": "028ed41ba1afb95bb86e0ae1536f3e9b4a2695fc8490b7d83033ac86440d59c5",
            "source": "amazon-inspector",
            "versions": [
                "0.1.4"
            ]
        },
        {
            "id": "IN-MAL-2026-005547",
            "import_time": "2026-06-11T05:41:05.778008819Z",
            "modified_time": "2026-06-11T05:06:33Z",
            "sha256": "82fa37e2478a7109e376e3a062ccb203806511033930eb7390e45fe7ef404b81",
            "source": "amazon-inspector",
            "versions": [
                "0.1.4"
            ]
        },
        {
            "id": "GHSA-2p34-5qgm-wr3f",
            "import_time": "2026-07-15T05:00:56.776230637Z",
            "modified_time": "2026-07-15T03:41:33Z",
            "ranges": [
                {
                    "events": [
                        {
                            "introduced": "0"
                        }
                    ],
                    "type": "SEMVER"
                }
            ],
            "sha256": "1a7e46df199f0d8dbede5404aab0ad253bb78bce77001d4b875d116806d9839d",
            "source": "ghsa-malware"
        }
    ]
}
References
Credits

Affected packages

npm / webpack-cache-cycle

Package

Name
webpack-cache-cycle
View open source insights on deps.dev
Purl
pkg:npm/webpack-cache-cycle

Affected ranges

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

Affected versions

0.*
0.1.4

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 
{
    "domains": [
        "jsonkeeper.com"
    ],
    "evidence_files": [
        {
            "path": "loader.js",
            "sha256": "a5ead14cb7532cc465ecd9f3330450e8bd6c35fca6b9d9dd2411344828294e83",
            "tlsh": "d2318a9e1ba52234da70d3d653235426d5a3e6327341e6c0b65c58d20fa2270d2b3dfc"
        },
        {
            "path": "package.json",
            "sha256": "7c1cfc32811eaeeab6a2241b72d6962048542cfb6afa7c042ce469f1bdf9e7ff",
            "tlsh": "a9f0c0284a646d3319e002c9085093f1f32ace6b09407c984bd3002c868e5b2abfe79e"
        }
    ],
    "package_integrity": [
        {
            "filename": "webpack-cache-cycle-0.1.4.tgz",
            "hashes": {
                "sha1": "c7adeafd40371553e4869ecb12567b99065f7067",
                "sha512_sri": "sha512-HTXEEsZQBAsvyKqTMd4+bkzmdmUxEW3HSNMXtrWJCghzTg9XI8436Q/I6xrDuCSJ4mseEmh+zwzkmxDG6ITkkw=="
            }
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/webpack-cache-cycle/MAL-2026-5579.json"