{"id":"MAL-2026-16264","title":"Malicious code in aiosendletter (PyPI)","summary":"Malicious code in aiosendletter (PyPI)","severity":"critical","exploited":true,"vendor":"aiosendletter","product":"aiosendletter","ecosystem":"pip","affected":["aiosendletter"],"published":"2026-09-17","updated":"2026-09-22","sourceUpdated":"2026-09-22T23:30:07.052853488Z","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/MAL-2026-16264","references":[{"url":"https://bad-packages.kam193.eu/pypi/package/aiosendletter"},{"url":"https://pypi.org/project/aiosendletter/4.3/"},{"url":"https://pypi.org/project/aiosendletter/4.6/"},{"url":"https://pypi.org/project/aiosendletter/3.8/"},{"url":"https://pypi.org/project/aiosendletter/4.5/"},{"url":"https://pypi.org/project/aiosendletter/3.9/"},{"url":"https://pypi.org/project/aiosendletter/0.2.0/"},{"url":"https://pypi.org/project/aiosendletter/3.7/"},{"url":"https://pypi.org/project/aiosendletter/4.1/"},{"url":"https://pypi.org/project/aiosendletter/4.0/"}],"tags":["osv","pip","malware"],"ingestedAt":"2026-09-18T16:21:29.478Z","slug":"MAL-2026-16264","body":"## Overview\n\n\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (29baa6f2cbfb2ef9907be7830505e33e82b5a1e6a45eb7f995022d09f5841f09)\nThe 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.\n\n## Source: kam193 (4e81e3b63bbe719f6d0bdd42930bb2f3235b8e41cbacf449743bb7dca67c9f08)\nPackage hides code to exfiltrate files. Most releases target unclear files, but some reveal the goal to exfiltrate sensitive Telegram data.\n\n\n---\n\nCategory: MALICIOUS - The campaign has clearly malicious intent, like infostealers.\n\n\nCampaign: 2026-09-aiosendletter\n\n\nReasons (based on the campaign):\n\n\n - files-exfiltration\n\n\n - target:telegram\n\n\n## Affected packages\n\n- `aiosendletter`\n\n## Remediation\n\nRefer to the advisory for the patched release.","depth":"abyssal","depthScore":70,"depthScoreParts":{"impact":52.3,"likelihood":0,"exploitation":18,"ransomware":0},"changes":[]}