platform-ui-codemodsnpm
Advisory published Updated
platform-ui-codemods is a confirmed malicious npm package (MAL-2026-12041) that executes malicious code on install (malicious version 20.6.7). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in platform-ui-codemods (npm)
What this malware does
On require() of the package, index.js loads./compat.js whose top-level init() downloads a platform-specific binary from a set of Cloudflare Workers mirrors whose hostnames are assembled at runtime from split-string arrays joined with.join("") (e.g. oob-worker.cf1*.workers.dev), with a DNS-TXT covert-channel fallback that reconstructs a base64 payload from chunked TXT records under c.<domain>/<n>.<domain> at *.dl.well1.site (tin/tina/ldr/win subdomains). The fetched bytes are written to a hidden/decoy path ("/tmp/.cache<hex>" on Unix, "%TEMP%\dotnet_diag_<hex>.exe" on Windows), chmod 0755, and spawned detached via /bin/sh -c or cmd.exe with a cooldown stamp file (".analytics_state") to avoid re-execution. Hostname obfuscation, decoy filenames, DNS-TXT egress fallback, and detached execution collectively indicate a staged remote-code-execution dropper that fires automatically on install/require of this package.
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.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for platform-ui-codemods (version 20.6.7).
If you installed it — respond
Remove platform-ui-codemods from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If platform-ui-codemods was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks platform-ui-codemods-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.