The d8s-netstrings for python, as distributed on PyPI, included a potential code-execution backdoor inserted by a third party. The backdoor is the democritus-strings package. The affected version is 0.1.0.
https://pypi.org/project/democritus-strings/
https://pypi.org/project/d8s-netstrings/
https://github.com/democritus-project/d8s-netstrings/issues/4