MalwarePublished 19 Jun 2026Updated 6 Jul 2026

eslint-helper (npm) · Malicious Code

Affects eslint-helperSource GCVE Database

Malicious package : remove eslint-helper and rotate any secrets on hosts that installed it.

Data as of 7 Jul 2026, 12:28 UTC

Classification

Malicious package

Published to npm · OSV MAL-2026-6187

What to do

Remove eslint-helper from every project, lockfile and image that pulls it in. Treat any host that installed it as compromised: rotate the credentials, tokens and keys it could read, from a clean machine.

Affected software

Product	Affected	Fixed in
npmeslint-helper	Affected =4.0.1 =4.0.2	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (5802f88a31cfb1c54196395aa04377de1c98657cdd78f59e4a595f2913239301) Package masquerades as an ESLint utility but contains no lint-related code. The exported from_str() recursively walks process.cwd() searching for secret-bearing files (.env, config.toml, Config.toml, config.json, env, id.json) and POSTs each file's contents to a hardcoded, base64-obfuscated endpoint at https://vercel-backend-five-vert.vercel.app/api/v1. A helper _gsh() additionally reads ~/.bash_history, ~/.zsh_history, fish history, and PowerShell PSReadLine ConsoleHost_history.txt, and shells out via execSync("bash -c history") and execSync("zsh -c 'fc -l -1000'") to dump in-memory shell history, then ships each to the same endpoint. All sensitive strings (target filenames, exfil URL, HTTP headers, USER env var name) are base64-obfuscated and decoded at module load via a decodeStr helper, indicating intentional evasion. Any project that requires this package and invokes from_str (or runs the shipped test.js) will leak credentials and shell history to the attacker. ## Source: ghsa-malware (a12235e67c9b0720356aa892ed51f2256ef30f7eb599f45b8d50eb9191aedd36) Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.

Impact

Systems with eslint-helper versions 4.0.1 or 4.0.2 installed or running are fully compromised. Sensitive files containing secrets and configuration data, as well as shell command histories, are exfiltrated to an attacker-controlled server. This leads to credential leakage, potential unauthorized access, and loss of confidentiality. The compromise may extend beyond the package itself, as attackers could have established persistent control. Removal of the package alone does not guarantee full remediation.

Defensive guidance

Immediate removal of eslint-helper versions 4.0.1 and 4.0.2 from all systems is strongly recommended. All secrets and credentials stored on affected systems should be considered compromised and rotated immediately using a secure, unaffected environment. Conduct a thorough investigation for additional persistence or malicious artifacts beyond the package. Monitor for suspicious activity and consider rebuilding compromised systems if full trust cannot be established.

Summary

The eslint-helper package versions 4.0.1 and 4.0.2 are malicious. The package exports a from_str() function that recursively scans the current working directory for files commonly containing secrets (.env, config.toml, config.json, etc.) and sends their contents to a base64-obfuscated, hardcoded URL on vercel.app. Additionally, a helper function _gsh() reads multiple shell history files across different shells and executes shell commands to dump in-memory shell history, exfiltrating all collected data to the same endpoint. The use of base64 encoding for sensitive strings and the exfiltration endpoint demonstrates deliberate evasion and malicious intent. Installing or running this package compromises the host system, potentially exposing all stored secrets and shell histories to attackers.

References

Community reviews

Loading reviews…

What to do

Affected software

Description

AI analysisMachine-generated, updated 7 Jul 2026, 00:07 UTC

Technical details

References

Community reviews