/usr/lib/x86_64-linux-gnu/libAfterConf.so.1 is in libafterstep1 2.2.12-6.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libAfterConf.so.1.17
/usr/lib/x86_64-linux-gnu/libAfterConf.so.1.17