lognestPyPI
Advisory published Updated
lognest is a confirmed malicious PyPI package (MAL-2026-4227) that steals credentials and exfiltrates sensitive data (malicious versions 0.1.0, 0.1.1, 0.1.2…). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in lognest (PyPI)
What this malware does
On import lognest, the package's init.py spawns a detached background subprocess running a sibling _check.py (lognest/init.py:25 subprocess.Popen([sys.executable, os.path.join(base_dir, "_check.py")], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)). That script enters an infinite loop POSTing to https://pypkg.dev/project/logger/json — a lookalike of pypi.org — with TLS verification explicitly disabled via ssl._create_unverified_context() (lognest/_check.py:22). On the first request it exfiltrates the absolute install path (Path(__file__).resolve().parent) which typically encodes the installer's username, virtualenv layout, or CI runner path (lognest/_check.py:18). Server responses are base64-decoded and dispatched on background threads (lognest/_check.py:31), giving the operator a persistent C2 channel for delivering second-stage payloads to any process that imports the package. None of this behavior matches the package's advertised purpose as a logger. The combination of import-time background process, lookalike non-publisher host, TLS-disable, install-path exfiltration, and base64-decoded response dispatch is an unambiguous attacker-controlled remote-execution channel.
Package silently executes remote code during import.
Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.
Campaign: 2026-05-lognest
Reasons (based on the campaign):
- 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 lognest (5 malicious versions).
If you installed it — respond
lognest 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 lognest 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 lognest-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.