MAL-2026-14588 Malicious code in yaml-report-formatter (PyPI)
- Package
- yaml-report-formatter
- Registry
- PyPI
What is MAL-2026-14588?
MAL-2026-14588 is a malicious package in yaml-report-formatter, published on 28 Aug 2026.
Official description
Package presents itself as a YAML report formatter but its top-level src/yaml_report_formatter/init.py starts a daemon thread on import that reads a token from /tmp/.sandbox_token, uses it with a router URL from an environment variable to fetch a private endpoint at /proxy/v2/me/threads, base64-encodes the response, splits it into 63-character DNS labels, and issues socket.getaddrinfo lookups against subdomains of dnshook.site to leak the data over a covert DNS side-channel. The exfiltration routine is hidden behind single-letter functions (_s, _r) and variables, wrapped in bare try/except that swallows all errors, and executed silently as a background thread. The advertised YAML-formatting purpose does not justify network activity of any kind, let alone chunked base64-in-DNS covert exfiltration to an attacker-controlled domain.
During import, the package collects sensitive information and exfiltrates it using DNS queries.
Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.
Campaign: 2026-08-ekx-report-utils
Reasons (based on the campaign):
targetted-attack
exfiltration-generic
exfiltration-credentials
What should I do about MAL-2026-14588?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.