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Malicious package

CaptchaCsharpNuGet

Malicious code in CaptchaCsharp (NuGet) Remove it immediately and rotate any exposed credentials.

MAL-2024-4433
Immediate action
Remove the package, then rotate any secrets the build/runtime could reach.
remove CaptchaCsharp

Malicious versions

52 flagged
3.2.33.2.43.2.53.2.63.2.73.2.83.2.93.2.103.2.113.2.123.2.133.2.143.2.153.2.163.2.173.2.183.2.193.2.203.2.213.2.223.2.233.2.243.2.253.2.263.2.273.2.283.2.293.2.303.2.313.2.323.2.333.2.343.2.353.2.363.2.373.2.383.2.393.2.403.2.413.2.423.2.433.2.443.2.453.2.463.2.473.2.483.2.493.2.503.2.513.2.527.0.07.0.1

Indicators of compromise (SHA-256)

ec2ca70300396a9e8fd2c7feb6cde52f2f2e65b15bb0103be5adf64f579b1238
e66e34d172c316669bb6229c507c5a7fcce1eced9f9a6c6be0a709e5ce807c11

Detection & response playbook

Malicious package
  1. Find it

    Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for CaptchaCsharp (52 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging CaptchaCsharp across your stack and pipelines.

  2. If you installed it — respond

    Remove CaptchaCsharp 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.

  3. Did it already run?

    If CaptchaCsharp 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.

  4. How O3 protects you

    O3 blocks CaptchaCsharp 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. CaptchaCsharp on NuGet has been identified as a malicious package (versions 3.2.3, 3.2.4, 3.2.5, 3.2.6, 3.2.7, 3.2.8, 3.2.9, 3.2.10, and 44 more flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2024-03231RLUA-2024-07647

References

Credits

  • ReversingLabs · finder

Detect & block this

O3 blocks CaptchaCsharp-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.

CaptchaCsharp (NuGet) malicious package — MAL-2024-4433 | O3 Security