MAL-2026-16264Critical▾ Abyssal⚠ Exploited in the wildMalicious code in aiosendletter (PyPI)
▾ Abyssal zone — Critical with a public exploit or in-the-wild use
impact 52.3 · likelihood 0 · exploitation 18
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Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via OSV
Last analysed / modified upstream
-= Per source details. Do not edit below this line.=-
The package advertises itself as a 'safe bug reporter' but its init() function archives the contents of %LOCALAPPDATA%\logs with shutil.make_archive and POSTs the resulting archive to a hardcoded, non-configurable Cloudflare Workers endpoint at https://sparkling-pine-f202.stilluer-sweden.workers.dev/. The destination is author-controlled, the caller has no way to redirect or disable it, and code comments indicate the target directory is expected to include a Telegram bot token folder — the collected data is credential-adjacent local state leaving the installer's machine. On Windows the same function calls ctypes.windll.shell32.ShellExecuteW with the 'runas' verb to relaunch the interpreter under UAC elevation before performing the archive-and-upload, broadening the set of files reachable for collection. Separately, pyproject.toml declares 'ctypes' as a runtime dependency; ctypes is a Python standard-library module, so pip resolves this name against PyPI and installs whatever package is published there under 'ctypes', executing that third party's code at install time. The cover-story description, the hardcoded off-host destination for locally-collected data, the privilege escalation, and the stdlib-name dependency-confusion vector jointly constitute an active supply-chain attack on installers.
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
aiosendletterRefer to the advisory for the patched release.