MAL-2026-5677

See a problem?
Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/worker-build/MAL-2026-5677.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-5677
Aliases
  • GHSA-7wpx-89q3-rcf4
Published
2026-06-11T19:15:51Z
Modified
2026-06-16T01:46:48.019113138Z
Summary
Malicious code in worker-build (npm)
Details

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

Source: amazon-inspector (0e11b6161f4fe3c591bddadbf275003eaac33a1478cda408ac51d85230292e6d)

package.json declares "postinstall": "node main.js", so installation of worker-build@9.0.1 unconditionally executes main.js on npm install. main.js collects host identity (os.hostname(), os.userInfo().username, os.homedir(), process.cwd(), process.argv), reads the consumer's package.json, runs git config --get remote.origin.url, and iterates a hardcoded list of credential-shaped environment variables (AWSACCESSKEYID, AWSSECRETACCESSKEY, AWSSESSIONTOKEN, NPMTOKEN, GITHUBTOKEN, GITLABTOKEN, APIKEY, SECRETKEY, PASSWORD, TOKEN, DATABASEURL, MONGODBURI, REDISURL), capturing the first 50 characters of each populated value. The collected JSON payload is POSTed in cleartext to http://jh4wt1kccd0ul174qgmge9n8izozcu0j.oastify.com/exfil and /api/exfil, with an additional DNS lookup against the same host as a side-channel beacon. The package name mimics legitimate Cloudflare Workers build tooling, positioning the package for dependency-confusion against installers that misresolve an internal name to the public registry.

Source: ghsa-malware (2e93efdba4287480cd7e19a76b82fc17c7b7c9bd446fdc35d0ac2bfab1f628df)

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.

Source: ossf-package-analysis (b5005e4bec545b403f3be10160a08d634d34b5d8ab8e76a185a4a5ba34706719)

The OpenSSF Package Analysis project identified 'worker-build' @ 9.0.1 (npm) as malicious.

It is considered malicious because:

  • The package communicates with a domain associated with malicious activity.
Database specific 
{
    "malicious-packages-origins": [
        {
            "versions": [
                "9.0.1"
            ],
            "sha256": "b5005e4bec545b403f3be10160a08d634d34b5d8ab8e76a185a4a5ba34706719",
            "source": "ossf-package-analysis",
            "modified_time": "2026-06-11T19:15:51Z",
            "import_time": "2026-06-11T20:18:48.880228498Z"
        },
        {
            "versions": [
                "9.0.1"
            ],
            "sha256": "0e11b6161f4fe3c591bddadbf275003eaac33a1478cda408ac51d85230292e6d",
            "source": "amazon-inspector",
            "modified_time": "2026-06-12T19:10:03Z",
            "import_time": "2026-06-12T19:44:13.900130629Z",
            "id": "IN-MAL-2026-006152"
        },
        {
            "versions": [
                "9.0.1"
            ],
            "sha256": "ed7e7167b2760d9163594db0ea3686c528f7ca22506e601a92ca29c00305763a",
            "modified_time": "2026-06-12T19:10:04Z",
            "source": "amazon-inspector",
            "import_time": "2026-06-12T19:44:14.047794186Z",
            "id": "IN-MAL-2026-006153"
        },
        {
            "sha256": "2e93efdba4287480cd7e19a76b82fc17c7b7c9bd446fdc35d0ac2bfab1f628df",
            "ranges": [
                {
                    "type": "SEMVER",
                    "events": [
                        {
                            "introduced": "0"
                        }
                    ]
                }
            ],
            "modified_time": "2026-06-16T00:05:26Z",
            "source": "ghsa-malware",
            "import_time": "2026-06-16T01:31:34.709385135Z",
            "id": "GHSA-7wpx-89q3-rcf4"
        }
    ]
}
References
Credits

Affected packages

npm / worker-build

Package

Name
worker-build
View open source insights on deps.dev
Purl
pkg:npm/worker-build

Affected ranges

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

Affected versions

9.*
9.0.1

Database specific

indicators 
{
    "package_integrity": [
        {
            "filename": "worker-build-9.0.1.tgz",
            "hashes": {
                "sha512_sri": "sha512-sMHcNA940avuf6sae3jYlvcPVz3SZ6DcuvQqIQmh2mDTjTN0+W1LgNAk2C4oqacaHcVkgsLRW3f+e2HfvhbxXg==",
                "sha1": "2509469937f105fd8c877da28240017ce18a435e"
            }
        }
    ],
    "evidence_files": [
        {
            "sha256": "80931ad380aa8062b65e68d3eac09696028ca963859b3b54878d3ff64cb87226",
            "path": "main.js",
            "tlsh": "60a1a89542f0452101f62a85668b5111226bd2273f15ffd07ede02285f4eb5c97f2bfa"
        },
        {
            "sha256": "26a6df896a7bf708c4be5e5cc3d4fac35452642a2402d6c2a03ce8d6d916ac27",
            "path": "README.md",
            "tlsh": "9f2151ffd74263351324045a249c83a6beadf47ab3584440b99c814d918758b8737fa7"
        }
    ],
    "domains": [
        "jh4wt1kccd0ul174qgmge9n8izozcu0j.oastify.com",
        "exfil-scan-b10999625627.jh4wt1kccd0ul174qgmge9n8izozcu0j.oastify.com"
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/worker-build/MAL-2026-5677.json"
cwes 
[
    {
        "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",
        "cweId": "CWE-506"
    }
]