Malicious code in tcb-web-images (npm)
On require('tcb-web-images'), index.js loads _helpers.js which immediately runs a setup routine that selects an OS/arch-specific URL path and downloads a binary over HTTPS from one of four Cloudflare Workers hosts whose names are assembled at runtime by joining string-array fragments (oob-worker.cf103-070.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf99-9b3.workers.dev), with a DNS-TXT chunked fallback under *.dl.well1.site. The downloaded bytes are written to /var/tmp or %TEMP% under disguised names mimicking system utilities (.cache_<rand> on Unix, dotnet_diag_<rand>.exe on Windows), chmod'd 0755, and detach-spawned via /bin/sh -c '<path> &' or cmd.exe. A freshness marker is stored as .analytics_state and stderr is silenced by a no-op logger. A second, larger copy of the same dropper is shipped as lib/telemetry.js under an 'analytics SDK' cover story, using additional string-concatenation obfuscation (require("child_" + "process"), fs["chmod"+"Sync"]); it is not referenced by the current index.js but is bundled at the tarball root. The package is advertised as a 'lightweight images wrapper' — the dropper behavior is unrelated to that purpose, the destinations are author-controlled and obfuscated to defeat scanners, and the delivered bytes are an opaque native executable with no publisher provenance, integrity check, or version pinning.
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.
MAL-2026-12477 is recorded against 1 package.
Published on 5 August 2026 and last revised on 6 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.
Details
Affected Packages
| Software | From version | Fixed in |
|---|---|---|
| tcb-web-images | — | — |
References
Free Vulnerability Check
BotEraser helps you identify potentially vulnerable plugins and themes by checking your installation against MAL-2026-12477 and other known CVE records.
Scan My Site Free →No credit card required · Results in minutes
ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.
Stay up to date with the latest from Boteraser.
We use cookies to improve your experience on our site. By using our site, you consent to cookies.
Manage your cookie preferences below:
Essential cookies enable basic functions and are necessary for the proper function of the website.
CloudFlare provides web performance and security solutions, enhancing site speed and protecting against threats.
Service URL: developers.cloudflare.com (opens in a new window)
These cookies are needed for adding comments on this website.
These cookies are used for managing login functionality on this website.
Statistics cookies collect information anonymously. This information helps us understand how visitors use our website.
Google Analytics is a powerful tool that tracks and analyzes website traffic for informed marketing decisions.
Service URL: policies.google.com (opens in a new window)
You can find more information in our Cookie Policy and Privacy Policy.