Which versions of tiktoken-mcp are malicious?

The following PyPI versions of tiktoken-mcp are flagged malicious: 0.13.1, 0.13.2. Treat any of these as compromised.

How do I remediate tiktoken-mcp if I installed it?

Remove tiktoken-mcp 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 network activity or persistence. Use O3 Security's dependency scanner to confirm the package and its artifacts are fully purged across your stack.

Is tiktoken-mcp part of a known attack campaign?

Yes — tiktoken-mcp is associated with the 2026-06-compr-woodpecker campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

Can O3 Security detect tiktoken-mcp in my codebase?

Yes. O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, blocking tiktoken-mcp and packages like it before any post-install script runs.

Malicious package

tiktoken-mcpPyPI

Malicious code in tiktoken-mcp (PyPI) Remove it immediately and rotate any exposed credentials.

MAL-2026-5326

Immediate action

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

pip uninstall tiktoken-mcp

What this malware does

Typosquatting package published from a compromised account with an embedded infostealer. The infostealer is a heavily obfuscated JavaScript code executed using Bun runtime on Python startup. It collects all kinds of sensitive data, including API keys, credentials to package repositories, cryptocurrency assets, password manager data. Infostealer actively queries online services to collect additional secrets as well as attempts to gain persistence and spread further by publishing infected packages using collected credentials. Data are exfiltrated likely using Github. The code seems to threaten to wipe the user's data if it detects invalid GitHub tokens. Cleanup should be done with caution.

It seems to be related to the recent Mini Shai Hulud campaign.

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

Campaign: 2026-06-compr-woodpecker

Reasons (based on the campaign):

compromised-package
exfiltration-env-variables
exfiltration-cloud-tokens
exfiltration-credentials
abuses-pth
obfuscation
infostealer
The package contains code to detect if it is running in a sandbox environment.
exfiltration-crypto
files-exfiltration
destructive-actions

Malicious versions

2 flagged

0.13.10.13.2

Indicators of compromise (SHA-256)

c9be15ab63daf09fd0949c09ea93f0d014aa6886b071ecc5a1af0dc4546d5a2a

05e1b139b928815987413cc4db186e23aceff0d04df4fabaf7c80813b9b154b4

Frequently asked questions

No. tiktoken-mcp on PyPI has been identified as a malicious package (versions 0.13.1, 0.13.2 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

2026-06-compr-woodpecker

References

Credits

Kamil Mańkowski (kam193) · analyst

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