@coopeuch/button@1.999.999
Coordinated vulnerability disclosure proof of concept for a dependency confusion issue.
AI Security Review
scanned 12d ago · by lpm-firewall-aiThe manifest automatically runs a hook that collects identifying host and consumer-project information and sends it to an external endpoint without an activation or consent guard. This is concrete install-time data exfiltration, so the package should be blocked.
Static reason
One or more suspicious static signals were detected.; source matched previously finalized malicious package; routed for review; source fingerprint signature matched known malicious package; routed for review
Trigger
The npm postinstall lifecycle runs during installation.
Impact
The recipient can learn identifying details about the host and the project that installed the package.
Mechanism
The hook gathers host, user, network, runtime, CI, and consuming project information, then sends a JSON report over HTTPS and makes a DNS lookup to the collector domain.
Attack narrative
The package's automatic install hook gathers host and project details and transmits them to an external collector. The hook also makes a DNS lookup using the package name and a collector-controlled subdomain.
AI rationale
The manifest automatically runs a hook that collects identifying host and consumer-project information and sends it to an external endpoint without an activation or consent guard. This is concrete install-time data exfiltration, so the package should be blocked.
Evidence
package.jsonpostinstall.js
Network endpoints2
collector.oob.s4yhii.com*.db03o8lag74hsugsg2j091t8mfcf437h3.oob.s4yhii.com
Decision evidence
public snapshotAI called this Malicious at 99.0% confidence as Malware with low false-positive risk.
Evidence for block
- The package runs postinstall.js automatically during installation.
- The hook assembles host, user, network, runtime, CI, and consumer project details into a report.
- The hook sends the report by HTTPS to collector.oob.s4yhii.com and also performs a DNS lookup to that domain.
Evidence against
- The source shows no shell execution, file writes, or persistence in the inspected hook.
Behavioral surface
EnvironmentVarsFilesystemNetwork
NoLicense
Source & flagged code
7 flagged · loading sourcepackage.jsonView file
•scripts.postinstall = node ./postinstall.js
High
Install Time Lifecycle Scripts
Package defines install-time lifecycle scripts.
package.jsonView on unpkg10"scripts": {
"postinstall": "node ./postinstall.js"
},
"files": [
"README.md
High
Suspicious Lifecycle Evidence
The package runs postinstall.js automatically during installation.
package.jsonView on unpkg · L10•scripts.postinstall = node ./postinstall.js
Medium
Ambiguous Install Lifecycle Script
Install-time lifecycle script is not statically allowlisted and needs review.
package.jsonView on unpkgpostinstall.jsView file
Findings
6 High3 Medium3 Low
HighInstall Time Lifecycle Scriptspackage.json
HighHost Fingerprint Exfiltrationpostinstall.js
HighKnown Malware Source Similaritypostinstall.js
HighKnown Malware Source Fingerprint Signaturepostinstall.js
HighSuspicious Lifecycle Evidencepackage.json
HighAi Review Evidencepostinstall.js
MediumAmbiguous Install Lifecycle Scriptpackage.json
MediumNetwork
MediumEnvironment Vars
LowScripts Present
LowFilesystem
LowNo License
Affected versions and remediation
This report applies to @coopeuch/button@1.999.999.
See all versions of @coopeuch/button for other recorded verdicts.
- Avoid installing @coopeuch/button@1.999.999. Remove it from direct dependencies and check your lockfile for transitive copies.
- Choose an independently verified alternative or release. This report does not establish that other versions are safe.
- If this version ran, investigate the affected machine and build environment. Rotate credentials it could access and rebuild from a trusted environment.
Evidence last updated: .
Source advisory published: .
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