What does the cardsmobile-rs-api malware do?

On require('cardsmobile-rs-api'), index.js loads _support.js, which reconstructs remote hosts via string-array join (oob-worker.cf103-070.workers.dev, cf102-baf.workers.dev, cf99-9b3.workers.dev) to hide the destinations from static analysis, downloads a platform-specific executable, writes it to /tmp or %TEMP% under a deceptive name such as dotnet_diag_ .exe, chmods it 0755, and detached-spawns it via child_process.spawn('/bin/sh') or spawn('cmd'). A DNS TXT-record fallback channel over sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru serves as an alternate transport. A TTL marker file (.analytics_state) gates the drop to fire once. The package has no real functional

Which versions of cardsmobile-rs-api are malicious?

The following npm versions of cardsmobile-rs-api are flagged malicious: 35.5.6. Treat any of these as compromised.

How do I remediate cardsmobile-rs-api if I installed it?

cardsmobile-rs-api is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.

I already installed cardsmobile-rs-api — how do I know if it already compromised me?

If cardsmobile-rs-api was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.

Is cardsmobile-rs-api part of a known attack campaign?

Yes — cardsmobile-rs-api is associated with the IN-MAL-2026-015244 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 cardsmobile-rs-api across my projects, lockfiles, and CI pipelines?

Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for cardsmobile-rs-api (version 35.5.6). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging cardsmobile-rs-api across your stack and pipelines.

Malicious package

cardsmobile-rs-apinpm

cardsmobile-rs-api is a confirmed malicious npm package (MAL-2026-12535) that steals credentials and exfiltrates sensitive data (malicious version 35.5.6). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in cardsmobile-rs-api (npm)

MAL-2026-12535

Immediate action

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

npm uninstall cardsmobile-rs-api

What this malware does

On require('cardsmobile-rs-api'), index.js loads support.js, which reconstructs remote hosts via string-array join (oob-worker.cf103-070.workers.dev, cf102-baf.workers.dev, cf99-9b3.workers.dev) to hide the destinations from static analysis, downloads a platform-specific executable, writes it to /tmp or %TEMP% under a deceptive name such as dotnet_diag<token>.exe, chmods it 0755, and detached-spawns it via child_process.spawn('/bin/sh') or spawn('cmd'). A DNS TXT-record fallback channel over sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru serves as an alternate transport. A TTL marker file (.analytics_state) gates the drop to fire once. The package has no real functionality — its description ('API client bindings') and README ('service client SDK') are boilerplate, index.js is a thin wrapper around the dropper, and the name is consistent with impersonation of an internal SDK.

Malicious versions

1 flagged

35.5.6

Indicators of compromise (SHA-256)

e561191e4649855e72a45b41f9fe45375ee5558a851e0c029dce070aa23d5608

Detection & response playbook

Credential / info stealer

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for cardsmobile-rs-api (version 35.5.6). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging cardsmobile-rs-api across your stack and pipelines.
If you installed it — respond
cardsmobile-rs-api is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If cardsmobile-rs-api was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks cardsmobile-rs-api before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.

Frequently asked questions

No. cardsmobile-rs-api on npm has been identified as a malicious package (version 35.5.6 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-015244

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks cardsmobile-rs-api-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.

Malware detection Runtime egress monitoring

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