registry / Data exfiltration / npm-show-date-proof-strings

npm-show-date-proof-strings

npm script for showing date strings

This report shows the evidence for npm-show-date-proof-strings@1.0.4. 1 of 2 known versions is blocked or flagged. See all versions.

AI Security Review

scanned 4mo ago · by lpm-firewall-ai

Direct source inspection confirms an install-time network callback that fingerprints and exfiltrates local user and host details. The behavior is unrelated to package functionality and is activated automatically during installation.

Static reason

One or more suspicious static signals were detected.; previous stored version diff introduced dangerous source

Trigger

npm install lifecycle postinstall

Impact

Leaks username, hostname, platform, and Node version to an external endpoint without user consent.

Mechanism

install-time host fingerprinting and HTTP callback

Attack narrative

On installation, npm runs package.json postinstall, which executes postinstall.js. The script gathers a nonce, event name, username via whoami/id/os.userInfo, hostname, platform, and Node version, logs the data, then sends it as query parameters to http://testnpm.byte.eyes.sh/npm-date-proof. This unconsented install-time callback is not needed for a date formatting package.

AI rationale

Evidence

package.jsonindex.jspostinstall.jsos.tmpdir()/npm-safe-proof-debug.log

Network endpoints1

testnpm.byte.eyes.sh/npm-date-proof

Decision evidence

public snapshot

AI called this Malicious at 98.0% confidence as Malware with low false-positive risk.

Evidence for block

package.json defines postinstall: node postinstall.js
postinstall.js runs automatically on install and sends HTTP callback
postinstall.js collects whoami, hostname, platform, and node version
postinstall.js executes whoami/id via child_process.execFile
postinstall.js writes debug log to os.tmpdir()

Evidence against

index.js only exports simple formatDate and hello helpers
No package files beyond package.json, index.js, and postinstall.js were present
No evidence of remote payload download or eval/vm/native loading

Behavioral surface

Source

ChildProcessFilesystemNetwork

Supply chain

UrlStrings

ManifestNo manifest risk signals triggered.

scanned 2 file(s), 3.04 KB of source, external domains: testnpm.byte.eyes.sh

Source & flagged code

5 flagged

package.jsonView file

•scripts.postinstall = node postinstall.js

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg

•scripts.postinstall = node postinstall.js

Medium

Ambiguous Install Lifecycle Script

Install-time lifecycle script is not statically allowlisted and needs review.

package.jsonView on unpkg

postinstall.jsView file

•matchType = previous_version_dangerous_delta matchedPackage = npm[redacted]@1.0.3 matchedIdentity = npm:[redacted]:1.0.3 similarity = 0.500 summary = stored previous version shares package body but lacks this dangerous source file

Critical

Previous Version Dangerous Delta

This package version adds a dangerous source file absent from the previous stored version.

postinstall.jsView on unpkg

1const http = require("http"); L2: const https = require("https"); ... L5: const path = require("path"); L6: const { execFile } = require("child_process"); L7: ... L32: }, L33: (err, stdout) => { L34: if (!err && stdout && stdout.trim()) { ... L43: async function getWhoami() { L44: if (process.platform === "win32") { L45: const result = await runCommand("whoami.exe"); ... L55: try {

High

Sandbox Evasion Gated Capability

Source gates dangerous network, credential, or execution behavior behind CI, host, platform, time, or geo fingerprint checks.

postinstall.jsView on unpkg · L1

High

Install Named Payload File

Install-named source file stages remote content through filesystem writes and execution.

postinstall.jsView on unpkg · L1

Source & flagged code

5 flagged · loading source

package.jsonView file

•scripts.postinstall = node postinstall.js

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg

•scripts.postinstall = node postinstall.js

Medium

Ambiguous Install Lifecycle Script

Install-time lifecycle script is not statically allowlisted and needs review.

package.jsonView on unpkg

postinstall.jsView file

Critical

Previous Version Dangerous Delta

This package version adds a dangerous source file absent from the previous stored version.

postinstall.jsView on unpkg

Findings

1 Critical3 High3 Medium3 Low

CriticalPrevious Version Dangerous Deltapostinstall.js

HighInstall Time Lifecycle Scriptspackage.json

HighSandbox Evasion Gated Capabilitypostinstall.js

HighInstall Named Payload Filepostinstall.js

MediumAmbiguous Install Lifecycle Scriptpackage.json

MediumNetwork

MediumStructural Risk Force Deep Review

LowScripts Present

LowFilesystem

LowUrl Strings

Affected versions and remediation

This report applies to npm-show-date-proof-strings@1.0.4.

The versions list below shows the verdict for each recorded version.

Avoid installing npm-show-date-proof-strings@1.0.4. 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: 2026-07-09 23:02:02.185Z (UTC).

Source advisory published: 2026-07-01 16:11:17.000Z (UTC).

Think this verdict is wrong? Dispute it on GitHub or read how reports are produced.

Versions

2 known versions

1.0.4latestshownMaliciousData ExfiltrationBlockPublishedJul 1, 2026, 4:26 PM 1.0.3SuspiciousMalwareWarnPublishedJul 1, 2026, 4:04 PM

AI Security Review

Decision evidence

Source & flagged code

Source & flagged code

Findings

Affected versions and remediation

Versions

Related packages

Other data exfiltration packages

Behavioral surface

Related packages

Other data exfiltration packages

Source & flagged code