Which versions of ultrafasttelethon are malicious?

The following PyPI versions of ultrafasttelethon are flagged malicious: 1.39.0, 1.39.0.1, 1.39.0.2, 1.39.0.3. Treat any of these as compromised.

How do I remediate ultrafasttelethon if I installed it?

ultrafasttelethon 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 ultrafasttelethon — how do I know if it already compromised me?

If ultrafasttelethon 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 ultrafasttelethon part of a known attack campaign?

Yes — ultrafasttelethon is associated with the 2025-04-fastgram 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 ultrafasttelethon 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 ultrafasttelethon (4 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging ultrafasttelethon across your stack and pipelines.

Malicious package

ultrafasttelethonPyPI

Malicious code in ultrafasttelethon (PyPI) Remove it immediately and rotate any exposed credentials.

MAL-2025-191915

Immediate action

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

pip uninstall ultrafasttelethon

What this malware does

Clone of Telethon package that exfiltrates credentials. See client/telegrambaseclient.py L608-626 (exfiltration function) and client/auth.py L163 (usage).

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

Campaign: 2025-04-fastgram

Reasons (based on the campaign):

clones-real-package
action-hidden-in-lib-usage
exfiltration-generic

Malicious versions

4 flagged

1.39.01.39.0.11.39.0.21.39.0.3

Indicators of compromise (SHA-256)

2f2335d63eb797b5edb8c95d3c5c088e72acab99487bbea8294706207e379ad0

73a960b0cd2d21f8bde61f22f956a4c2a02ccddd9e1277eef23d3d8e0406cba4

29602e2cd7f36a4d478bdcd0bb75c12f7c61a35d253b73bd36f9a1e6975adab2

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 ultrafasttelethon (4 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging ultrafasttelethon across your stack and pipelines.
If you installed it — respond
ultrafasttelethon 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 ultrafasttelethon 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 ultrafasttelethon 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. ultrafasttelethon on PyPI has been identified as a malicious package (versions 1.39.0, 1.39.0.1, 1.39.0.2, 1.39.0.3 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

2025-04-fastgram

References

bad-packages.kam193.eu

Credits

Kamil Mańkowski (kam193)

Detect & block this

O3 blocks ultrafasttelethon-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