MalwarePublished 12 Aug 2026

thundertiger (npm) · Malicious Code

Affects thundertigerSource GCVE Database

Malicious package : remove thundertiger and rotate any secrets on hosts that installed it.

Data as of 12 Aug 2026, 16:40 UTC

Classification

Malicious package

Published to npm · OSV MAL-2026-13834

What to do

Remove thundertiger 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
npmthundertiger	Affected =1.0.0	Fixed in–

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Description

The npm package 'thundertiger' version 1.0.0 contains malicious code in a single HTML file that mimics a Cloudflare security challenge. The embedded obfuscated script redirects users to an external phishing site. Installing or requiring the package does not execute the payload on the developer's machine, but end users loading the hosted HTML are targeted. This is an abuse of the npm registry as a CDN for phishing rather than a direct installer-side attack. The package should be removed and secrets rotated if installed, as the system may be fully compromised.

Impact

End users who load the malicious HTML content are redirected to an external phishing site, potentially exposing them to credential theft or other attacks. Systems with the package installed should be considered fully compromised, as the package may have been used to deploy additional malicious software. All secrets and keys on affected systems should be rotated from a clean environment. Removal of the package alone may not eliminate all malicious components.

Defensive guidance

Remove the 'thundertiger' package version 1.0.0 immediately if installed. Rotate all secrets and keys from a different, uncompromised system. Conduct a thorough security review of affected systems to detect and remediate any additional malware or persistence mechanisms. Coordinate with the npm registry to report and request takedown of the malicious package to prevent further abuse. Since the malicious payload is delivered via hosted HTML content, avoid loading or serving this content from untrusted sources.

References

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What to do

Affected software

Description

AI analysisMachine-generated, updated 12 Aug 2026, 16:40 UTC

Technical details

References

Community reviews