bytekitPyPI
bytekit is a confirmed malicious PyPI package (MAL-2026-6751) that steals credentials and exfiltrates sensitive data (malicious versions 3.4.1, 3.4.2). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in bytekit (PyPI)
What this malware does
The package was found to contain malicious code or consuming dependency that contains malicious code
The campaign consists of multiple packages. The trigger sits in the package 'procwire,' which depends on two others. During installation, procwire uses schemavault and bytekit packages. The first one holds the URL holding malware (in two places, once as steganography in the bundled image and once as a fallback just as a list of encoded bytes). The bytekit implements simple custom decoding used to retrieve back the URL in the fallback method. Additionally, procwire is also a dependency of confighub, turning another package into malware. The downloaded executable is run and quickly removed. The executable likely contains an infostealer and contacts the domain 030502[.]xyz
Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.
Campaign: 2026-07-procwire
Reasons (based on the campaign):
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The package overrides the install command in setup.py to execute malicious code during installation.
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Downloads and executes a remote executable.
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obfuscation
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The malicious code is intentionally included in a dependency of the package
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malware
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steganography
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Search your lockfiles and build artifacts for bytekit (2 malicious versions).
If you installed it — respond
bytekit 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 bytekit 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
Campaign
References
Credits
- Amazon Inspector · finder
- Kamil Mańkowski (kam193) · reporter
Detect & block this
O3 blocks bytekit-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.