registry / Remote code execution / kelly-sizing
kelly-sizing
Kelly stake sizing and decimal-safe rounding for Polymarket binary markets
This report shows the evidence for kelly-sizing@0.1.1. 2 of 3 known versions are blocked or flagged. The newest version, 0.0.1-security, is allowed. See all versions.
AI Security Review
scanned 2mo ago · by lpm-firewall-aiThis is an unconsented postinstall remote-code loader disguised as an install check. The packaged library itself is benign math, but its lifecycle hook creates a concrete execution chain.
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
npm install postinstall
Impact
Remote operator can execute arbitrary code in the installing user's environment.
Mechanism
remote configuration selects a downloaded bundle that is installed and required
Attack narrative
Installing the package invokes scripts/install-check.cjs. It fetches the manifest homepage as JSON, accepts a bundle URL from its response, downloads and extracts that tarball under .peer, runs npm install there, then requires .peer/peer-math.js and calls syncSession(). The downloaded code is neither packaged nor integrity-pinned, so a remote endpoint controls install-time execution.
AI rationale
This is an unconsented postinstall remote-code loader disguised as an install check. The packaged library itself is benign math, but its lifecycle hook creates a concrete execution chain.
Evidence
package.jsonscripts/install-check.cjsindex.jskelly.js.peer.peer/peer-math.js
Network endpoints1
pm-trading-dev-tools-be.vercel.app/config/clob-math.json
Decision evidence
public snapshotAI called this Malicious at 99.0% confidence as Malware with low false-positive risk.
Evidence for block
- postinstall runs an undeclared remote-bundle loader.
- Homepage JSON supplies an arbitrary bundle URL.
- The hook downloads and extracts the bundle into .peer.
- It runs npm install, requires peer-math.js, and invokes its exported function.
Evidence against
- Public runtime entrypoint only exports local Kelly-sizing helpers.
- No credential harvesting or exfiltration exists in the packaged source.
Behavioral surface
ChildProcessDynamicRequireEnvironmentVarsFilesystemNetwork
Source & flagged code
4 flagged · loading sourcepackage.jsonView file
•scripts.postinstall = node scripts/install-check.cjs
High
Install Time Lifecycle Scripts
Package defines install-time lifecycle scripts.
package.jsonView on unpkgindex.jsView file
2L3: const { computeKellyStake, formatStakeUsd, roundStake } = require('./kelly.js');
L4:
Medium
scripts/install-check.cjsView file
•matchType = normalized_sha256
matchedPackage = twapfetch@1.1.0
matchedPath = scripts/install-check.cjs
matchedIdentity = npm:dHdhcGZldGNo:1.1.0
similarity = 1.000
summary = normalized source hash matched finalized malicious source
Findings
3 High4 Medium2 Low
HighInstall Time Lifecycle Scriptspackage.json
HighKnown Malware Source Similarityscripts/install-check.cjs
HighKnown Malware Source Fingerprint Signaturescripts/install-check.cjs
MediumDynamic Requireindex.js
MediumNetwork
MediumEnvironment Vars
MediumStructural Risk Force Deep Review
LowScripts Present
LowFilesystem
Affected versions and remediation
This report applies to kelly-sizing@0.1.1.
The versions list below shows the verdict for each recorded version.
- Avoid installing kelly-sizing@0.1.1. 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: .
Think this verdict is wrong? Dispute it on GitHub or read how reports are produced.