virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.7, the bash activate script escapes the environment name for only one of the two passes bash makes over PS1, so a backslash in the name undoes the escaping and a name containing \$(...) runs as commands in the user's shell each time bash draws the prompt. This issue is fixed in version 21.14.7.
https://github.com/pypa/virtualenv/security/advisories/GHSA-vxj4-q4g9-crj7
https://github.com/pypa/virtualenv/releases/tag/21.14.7
https://github.com/pypa/virtualenv/commit/c3104e02474b652832a9bbaae79f6e1696296932