MalwarePublished 17 Sep 2026Updated 22 Sep 2026

aiosendletter (PyPI) · Malicious Code

Affects aiosendletterSource GCVE Database

Malicious package : remove aiosendletter and rotate any secrets on hosts that installed it.

Data as of 26 Oct 2026, 16:20 UTC

Classification

Malicious package

Published to PyPI · OSV MAL-2026-16264

What to do

Remove aiosendletter from every project, lockfile and image that pulls it in. Treat any host that installed it as compromised: rotate the credentials, tokens and keys it could read, from a clean machine.

Affected software

Product	Affected	Fixed in
PyPIaiosendletter	Affected 0.2.0 – 4.6 9 affected builds	Fixed in–

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Description

--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (46b706e618e75dd4f864a55a33a06cfa98c890d310735b1dea71ad86fe299fe6) The package ships a module (e.py) that prompts for administrator elevation via UAC, archives the contents of %LOCALAPPDATA%\logs with shutil.make_archive, and POSTs the resulting zip to a hardcoded attacker-controlled endpoint at https://sparkling-pine-f202.stilluer-sweden.workers.dev/ using requests.post. The %LOCALAPPDATA%\logs tree commonly contains Discord, browser, and game-tool artifacts including session data. The package's PyPI summary ("Safe bug reporter for sending local logs via Cloudflare Workers") and identifiers such as aiosendletter_logs are cover-story framing for bulk exfiltration of installer-owned data. Separately, pyproject.toml declares the Python stdlib name "ctypes" as an unpinned PyPI runtime dependency, causing pip to resolve and install whatever package currently occupies that registry name and execute its lifecycle code on the installer's machine — a dependency-confusion install-time code path in addition to the primary stealer payload. ## Source: kam193 (4e81e3b63bbe719f6d0bdd42930bb2f3235b8e41cbacf449743bb7dca67c9f08) Package hides code to exfiltrate files. Most releases target unclear files, but some reveal the goal to exfiltrate sensitive Telegram data. --- Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers. Campaign: 2026-09-aiosendletter Reasons (based on the campaign): - files-exfiltration - target:telegram

Impact

Users who install or run the affected versions of 'aiosendletter' risk unauthorized exfiltration of local log files that may contain sensitive session information from applications like Discord, browsers, game tools, and Telegram. The package also introduces a supply chain risk via dependency confusion by referencing an unpinned standard library package name, potentially executing arbitrary code during installation. This can lead to significant privacy breaches and compromise of user credentials or session tokens.

Defensive guidance

Users should immediately avoid installing or using the 'aiosendletter' package, especially the affected versions. Remove any installations of this package from systems. Monitor for and block network traffic to the known malicious endpoint. Verify dependencies carefully to avoid dependency confusion attacks, ensuring that standard library packages are not overridden by malicious PyPI packages. Check vendor advisories or PyPI security notices for updates or removal of the malicious package.

Summary

The 'aiosendletter' package on PyPI ships with a malicious module 'e.py' that prompts for UAC elevation, archives the contents of the %LOCALAPPDATA%\logs directory (which may contain Discord, browser, and game-tool session data), and exfiltrates this archive via HTTP POST to a hardcoded attacker-controlled endpoint. The package's description and identifiers are deceptive, framing it as a legitimate bug reporter. Furthermore, the package's pyproject.toml declares the Python standard library package 'ctypes' as an unpinned runtime dependency, allowing pip to resolve and install a potentially malicious package from PyPI during installation, representing a dependency confusion vector. Some releases explicitly target Telegram data for exfiltration. This behavior classifies the package as a malicious infostealer.

References

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What to do

Affected software

Description

AI analysisMachine-generated, updated 18 Sep 2026, 01:06 UTC

Technical details

References

Community reviews