/usr/lib/mono/2.0/Microsoft.Build.Framework.dll is in libmono-microsoft-build2.0-cil 3.2.8+dfsg-10.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/mono/2.0/../gac/Microsoft.Build.Framework/2.0.0.0__b03f5f7f11d50a3a/Microsoft.Build.Framework.dll