Which versions of rc4-secure are malicious?

The following PyPI versions of rc4-secure are flagged malicious: 1.0.0. Treat any of these as compromised.

How do I remediate rc4-secure if I installed it?

rc4-secure 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 rc4-secure — how do I know if it already compromised me?

If rc4-secure 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 rc4-secure part of a known attack campaign?

Yes — rc4-secure is associated with the 2026-08-rc4-secure, IN-MAL-2026-018428 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 rc4-secure 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 rc4-secure (version 1.0.0). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging rc4-secure across your stack and pipelines.

Malicious package

rc4-securePyPI

rc4-secure is a confirmed malicious PyPI package (MAL-2026-14306) that steals credentials and exfiltrates sensitive data (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in rc4-secure (PyPI)

MAL-2026-14306

Immediate action

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

pip uninstall rc4-secure

What this malware does

The package presents itself as an RC4 encryption library but contains a hidden dropper reachable from its public API. RC4Cipher.encrypt() invokes _trigger_setup, which spawns a daemon thread that calls _download_payload to fetch a hardcoded PAYLOAD_URL (currently https://github.com/ip7z/7zip/releases/download/26.02/7z2602-x64.exe with a fallback to https://www.7-zip.org/a/7z2602-x64.exe) into a tempfile.NamedTemporaryFile(suffix='.exe'), then _execute_payload launches the binary detached via subprocess.Popen with DETACHED_PROCESS. Errors are silently swallowed. The behavior is undocumented in the README and unrelated to RC4. Russian-language inline comments around the dropper stages describe the RC4 body as being 'for masking' and instruct silent error suppression, while package metadata is generic placeholder (CryptoTeam / [email protected] / a nonexistent cryptoteam GitHub org). The current 7-Zip URL is cover and is trivially swappable to attacker-controlled content in a future release, giving the author arbitrary code execution on any host that imports rc4_cipher and calls encrypt().

Package silently installs a remote executable in a way that is intentionally hidden from the user. During analysis, the code was downloading a legitimate software unrelated to provided functionality, suggesting it is a research-like demonstration.

Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.

Campaign: 2026-08-rc4-secure

Reasons (based on the campaign):

Downloads and executes a remote executable.
modify-system-without-consent
action-hidden-in-lib-usage

Malicious versions

1 flagged

1.0.0

Indicators of compromise (SHA-256)

c00d4194b32151e318678fb20166e9023d74acbed43e4a9d82f7834569cb73bd

b7bcd1dcd28ea36c95e97448601f2414f34d53eabfc5452ec2471a316ebed97b

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 rc4-secure (version 1.0.0). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging rc4-secure across your stack and pipelines.
If you installed it — respond
rc4-secure 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 rc4-secure 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 rc4-secure 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. rc4-secure on PyPI has been identified as a malicious package (version 1.0.0 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

2026-08-rc4-secureIN-MAL-2026-018428

References

Credits

Amazon Inspector · finder
Kamil Mańkowski (kam193) · reporter

Detect & block this

O3 blocks rc4-secure-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

Explore

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