webreaderPyPI
Advisory published Updated
webreader is a confirmed malicious PyPI package (MAL-2026-17757) that steals credentials and exfiltrates sensitive data (malicious version 2.3.8). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in webreader (PyPI)
What this malware does
In this campaign, the main package (webreader) has an embeded pickle disguised as a config. A related dependency (pafer) contains code to load the pickle. During unpickling, malicious code embeded in the pickle file is automatically executed. It then establishes persistence via a PTH file and downloads the next stage payload. It finally acts like a RAT, allowing remote exfiltration and code execution.
Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.
Campaign: 2026-10-webreader
Reasons (based on the campaign):
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rat
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Downloads and executes a remote malicious script.
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obfuscation
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The package contains code to execute remote commands (probably limited to a specific set) on the victim's machine.
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abuses-pth
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persistence
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The malicious code is intentionally included in a dependency of the package
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files-exfiltration
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Search your lockfiles and build artifacts for webreader (version 2.3.8).
If you installed it — respond
webreader 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 webreader 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
- Kamil Mańkowski (kam193) · reporter
Detect & block this
O3 blocks webreader-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.