/usr/lib/linux-tools/4.15.0-43-generic/perf is in linux-tools-4.15.0-43-generic 4.15.0-43.46.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/linux-tools/4.15.0-43-generic/../../linux-tools-4.15.0-43/perf