rlaskPyPI
Advisory published Updated
rlask is a confirmed malicious PyPI package (MAL-2026-5303) that steals credentials and exfiltrates sensitive data (malicious versions 3.1.3, 3.1.4, 3.1.5…). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in rlask (PyPI)
What this malware does
The package name 'rlask' is a single-character edit of the popular 'flask' package. METADATA declares 'Maintainer-email: Pallets [email protected]', and entry_points.txt registers 'flask=flask.cli:main' rather than an rlask-specific entry — indicating the distribution is a verbatim repackaging of Flask 3.1.x source while falsely advertising Pallets maintainership. The exported API (Flask, Blueprint, Config, request, session, etc.) mirrors Flask's surface. No exfiltration, install-time hooks, subprocess execution, credential reads, or outbound network I/O were observed in the shipped code. The risk is name confusion plus forged maintainer identity: a developer who mistypes 'pip install flask' as 'pip install rlask' receives a package that shadows the real Flask, controlled by an author who is not Pallets and could push a malicious update at any time. Routing to human review per the typosquat handling discipline — name-confusion judgments and impersonated-maintainer attributions should be confirmed by a human before publication.
Typosquatting package published from a compromised account with an obfuscated infostealer. The infostealer is a heavily obfuscated JavaScript code executed using Bun runtime on Python startup. It collectes 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):
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compromised-package
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exfiltration-env-variables
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exfiltration-cloud-tokens
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exfiltration-credentials
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abuses-pth
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obfuscation
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infostealer
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The package contains code to detect if it is running in a sandbox environment.
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exfiltration-crypto
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files-exfiltration
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destructive-actions
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Search your lockfiles and build artifacts for rlask (5 malicious versions).
If you installed it — respond
rlask 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 rlask 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 rlask-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.