bnpl-blocks-design-systemnpm
Advisory published Updated
bnpl-blocks-design-system is a confirmed malicious npm package (MAL-2026-12910) that executes malicious code on install (malicious version 35.4.8). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in bnpl-blocks-design-system (npm)
What this malware does
On require(), support.js fetches a platform-specific binary from obfuscated hosts assembled by array-join fragments (oob-worker.cf99-9b3.workers.dev mirrors) and, on HTTPS failure, reassembles a base64 payload from TXT records under sdk/ext/pkg/net.dl.wel1.ru. The fetched bytes are written to /var/tmp or %TEMP% under cover-story names (analytics_state, dotnet_diag.exe,.cache_), chmod 0755 on Unix, and spawned detached via /bin/sh -c or cmd.exe /c start /b. The package advertises itself as a design system but ships no design-system code path that would need to fetch and execute native binaries, and the destination hosts, filenames, and delivery channel are all obfuscated. Any consumer that installs and imports this package executes attacker-controlled code on the installer host at import time.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for bnpl-blocks-design-system (version 35.4.8).
If you installed it — respond
Remove bnpl-blocks-design-system 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 bnpl-blocks-design-system 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 bnpl-blocks-design-system-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.