Which versions of boxy-expander-contract are malicious?

The following npm versions of boxy-expander-contract are flagged malicious: 35.5.3. Treat any of these as compromised.

How do I remediate boxy-expander-contract if I installed it?

Remove boxy-expander-contract 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 boxy-expander-contract — how do I know if it already compromised me?

If boxy-expander-contract 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 boxy-expander-contract part of a known attack campaign?

Yes — boxy-expander-contract is associated with the IN-MAL-2026-015344 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 boxy-expander-contract across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for boxy-expander-contract (version 35.5.3).

Malicious package

boxy-expander-contractnpm

Advisory published Aug 5, 2026Updated Aug 5, 2026

boxy-expander-contract is a confirmed malicious npm package (MAL-2026-13043) that executes malicious code on install (malicious version 35.5.3). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in boxy-expander-contract (npm)

MAL-2026-13043

Immediate action

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

npm uninstall boxy-expander-contract

What this malware does

On require() of this package, index.js loads./runtime.js which assembles Cloudflare Workers hostnames via string-split.join('') fragments (e.g. oob-worker.cf103-070.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf101-adf.workers.dev) with a DNS-TXT fallback under *.dl.wel1.ru (sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, net.dl.wel1.ru), downloads a platform-specific binary via https.get, writes it to /tmp or %TEMP% under a name masquerading as system tooling (dotnet_diag.exe,.cache_), chmods 755 on unix, and spawns it detached via spawn('/bin/sh', ['-c',...]) or spawn('cmd',...). No hash or signature verification is performed and destination hosts are string-fragmented to evade static analysis. The package's advertised API is an unrelated decoy stub.

Malicious versions

1 flagged

35.5.3

Indicators of compromise (SHA-256)

d1f5856de3b0385535e80e5ef85627ecb7a087132c82c5d5457b35b62b9eaf72

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for boxy-expander-contract (version 35.5.3).
If you installed it — respond
Remove boxy-expander-contract 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 boxy-expander-contract 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. boxy-expander-contract on npm has been identified as a malicious package (version 35.5.3 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-015344

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks boxy-expander-contract-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