flashsimpleloggerPyPI
Advisory published Updated
flashsimplelogger is a confirmed malicious PyPI package (MAL-2025-191729) that steals credentials and exfiltrates sensitive data (malicious versions 0.1.0, 0.2.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in flashsimplelogger (PyPI)
What this malware does
It's a clone of "loguru" package which on import loads a second-stage script from loguru[.]guru. This makes a few checks and downloads the next stage, which is a code obfuscated with PyArmor with unclear behaviour.
The way the malicious code has been embedded could be called a "sophisticated" threat. The code is in the _logger.py in two places: the payload in L2242 as a long string constraint of only whitespaces, which are then transformed into bits and bytes, and later compiled and executed using "types.FunctionType" during initialisation of Core class.
Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.
Campaign: 2025-07-loquru
Reasons (based on the campaign):
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typosquatting
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obfuscation
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clones-real-package
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Downloads and executes a remote malicious script.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Search your lockfiles and build artifacts for flashsimplelogger (2 malicious versions).
If you installed it — respond
flashsimplelogger 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 flashsimplelogger 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)
Detect & block this
O3 blocks flashsimplelogger-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.