@coopeuch/common@1.999.999
Coordinated vulnerability disclosure proof of concept for a dependency confusion issue.
AI Security Review
scanned 12d ago · by lpm-firewall-aiThe automatic install hook collects identifying host and environment information and transmits it to an external endpoint without an opt-in. This is concrete install-time data exfiltration.
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
Package installation runs the postinstall hook.
Impact
An external recipient receives identifying information about the host and its build environment.
Mechanism
The hook builds a report from operating system, user, machine, network, and install context, then sends it in an HTTPS POST request.
Attack narrative
During installation, the package collects host and user identifiers and environment details, then posts the report to collector.oob.s4yhii.com. The hook runs without an explicit opt-in. Although the report filters environment variables to names only, it includes identifying host information and network details.
AI rationale
The automatic install hook collects identifying host and environment information and transmits it to an external endpoint without an opt-in. This is concrete install-time data exfiltration.
Evidence
package.jsonpostinstall.js
Network endpoints1
collector.oob.s4yhii.com
Decision evidence
public snapshotAI called this Malicious at 98.0% confidence as Malware with low false-positive risk.
Evidence for block
- package.json runs postinstall.js automatically during installation.
- postinstall.js collects host and user identity, install paths, network interface details, and machine characteristics.
- postinstall.js sends the report by HTTPS POST to collector.oob.s4yhii.com.
- The postinstall path invokes the send routine without an opt-in gate.
Evidence against
- The hook filters environment variables by name and does not include their values in its report.
- The package entry point is a placeholder module; the reported collection and network behavior is in the install 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"
},
"file
High
Suspicious Lifecycle Evidence
package.json 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
HighSuspicious Lifecycle Evidencepostinstall.js
MediumAmbiguous Install Lifecycle Scriptpackage.json
MediumNetwork
MediumEnvironment Vars
LowScripts Present
LowFilesystem
LowNo License
Affected versions and remediation
This report applies to @coopeuch/common@1.999.999.
See all versions of @coopeuch/common for other recorded verdicts.
- Avoid installing @coopeuch/common@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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