Which versions of bnpl-blocks-sanitizer are malicious?

The following npm versions of bnpl-blocks-sanitizer are flagged malicious: 35.1.8. Treat any of these as compromised.

How do I remediate bnpl-blocks-sanitizer if I installed it?

Remove bnpl-blocks-sanitizer 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.

I already installed bnpl-blocks-sanitizer — how do I know if it already compromised me?

If bnpl-blocks-sanitizer 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.

Is bnpl-blocks-sanitizer part of a known attack campaign?

Yes — bnpl-blocks-sanitizer is associated with the IN-MAL-2026-015373 campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

How do I find bnpl-blocks-sanitizer across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for bnpl-blocks-sanitizer (version 35.1.8).

Malicious package

bnpl-blocks-sanitizernpm

Advisory published Aug 5, 2026Updated Aug 5, 2026

bnpl-blocks-sanitizer is a confirmed malicious npm package (MAL-2026-13014) that executes malicious code on install (malicious version 35.1.8). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in bnpl-blocks-sanitizer (npm)

MAL-2026-13014

Immediate action

Remove the package, then rotate any secrets the build/runtime could reach.

npm uninstall bnpl-blocks-sanitizer

What this malware does

On require(), index.js loads polyfill.js which selects a platform-specific endpoint and downloads an opaque binary from hardcoded Cloudflare Workers subdomains (oob-worker.cf103-070.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf102-baf.workers.dev), with DNS-TXT chunked-base64 fallback resolution against sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru. The fetched bytes are written to /tmp or %TEMP% under disguised names such as dotnet_diag.exe and.cache_, chmodded to 0o755, and spawned detached via cmd.exe /c start /b on Windows or /bin/sh -c on POSIX. Destination hostnames are assembled by joining split-string fragments to evade static scanners, and comments frame the behavior as 'telemetry' and 'analytics_state' while the actual operation is fetch-and-execute of an unpinned, unverified binary from hosts unrelated to the package publisher. There is no hash or signature verification, no pinning, and execution fires as a side effect of importing the package.

Malicious versions

1 flagged

35.1.8

Indicators of compromise (SHA-256)

a0d15dd8da5871696be88e0e89993a693b85554134facad7dbec47b844f13d87

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for bnpl-blocks-sanitizer (version 35.1.8).
If you installed it — respond
Remove bnpl-blocks-sanitizer 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-sanitizer 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

No. bnpl-blocks-sanitizer on npm has been identified as a malicious package (version 35.1.8 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-015373

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks bnpl-blocks-sanitizer-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.

Malware detection Runtime egress monitoring

Explore

All malware advisories How O3 detects malware Vulnerability database