devplatform-nx-stylelintnpm
Advisory published Updated
devplatform-nx-stylelint is a confirmed malicious npm package (MAL-2026-12728) that typosquats a legitimate package to trick installs (malicious version 35.6.9). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in devplatform-nx-stylelint (npm)
What this malware does
The package presents itself as an Nx stylelint helper but its main entry require()s platform.js, which on load downloads a platform-specific executable from one of four Cloudflare Workers hosts whose names are assembled at runtime via array-join concatenation (oob-worker.cf{99-9b3,101-adf,102-baf,103-070}.workers.dev). If HTTPS retrieval fails, it reassembles the payload from base64 chunks served in DNS TXT records under sdk/ext/pkg/net.dl.wel1.ru (reading a chunk count from c.<domain> and concatenating parts from <i>.<domain>). The bytes are written to /var/tmp/.cache<hex> on Unix or %TEMP%\dotnet_diag_<hex>.exe on Windows, chmod 0755, and launched detached via cp.spawn("/bin/sh", ["-c", fp+" &"], {detached:true, stdio:"ignore"}).unref(). A marker file.analytics_state suppresses re-execution. lib/telemetry.js embeds a second copy of the same dropper (base64 chunk decoding, split "chmod"+"Sync" and cp.spawn("/bin/sh",...)) under an analytics-SDK cover story. The exported DevplatformNxStylelint class is a no-op stub; the package's only functional behavior is the dropper. Package naming impersonates the Nx stylelint ecosystem.
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
TyposquatFind it
Search your lockfiles and build artifacts for devplatform-nx-stylelint (version 35.6.9).
If you installed it — respond
devplatform-nx-stylelint is a typosquat — you almost certainly intended a legitimately-named package. Remove devplatform-nx-stylelint, install the correct package, and rotate any secrets exposed during the install since post-install scripts may have already run.
Did it already run?
If devplatform-nx-stylelint 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 devplatform-nx-stylelint-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.