Which versions of fastertelethon are malicious?

The following PyPI versions of fastertelethon are flagged malicious: 1.0.0, 1.0.5. Treat any of these as compromised.

How do I remediate fastertelethon if I installed it?

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

If fastertelethon 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 fastertelethon part of a known attack campaign?

Yes — fastertelethon 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 fastertelethon across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for fastertelethon (2 malicious versions).

Malicious package

fastertelethonPyPI

Advisory published Apr 4, 2025Updated Dec 31, 2025

fastertelethon is a confirmed malicious PyPI package (MAL-2025-191723) that steals credentials and exfiltrates sensitive data (malicious versions 1.0.0, 1.0.5). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in fastertelethon (PyPI)

MAL-2025-191723

Immediate action

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

pip uninstall fastertelethon

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

2 flagged

1.0.01.0.5

Indicators of compromise (SHA-256)

b24babfe443100b225270a7cc7bff07ed10e39121be0694653ec59a91ef88a3b

3ccfc281c2541df7e1354e6de8c64624fdc75dcc229d33962b171b0a95087edf

ca8244ca6a84b757f58716bc8bb3a219e381ba136bb9c637d29fc549f928cef6

8ab64081fd1ef60d3b7ca9424cbe8653e1b3716d9fc8bb721919501ccef08714

Detection & response playbook

Credential / info stealer

Find it
Search your lockfiles and build artifacts for fastertelethon (2 malicious versions).
If you installed it — respond
fastertelethon 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 fastertelethon 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. fastertelethon on PyPI has been identified as a malicious package (versions 1.0.0, 1.0.5 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 fastertelethon-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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