/usr/share/java/build-helper-maven-plugin.jar is in libbuild-helper-maven-plugin-java 1.5-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/java/../maven-repo/org/codehaus/mojo/build-helper-maven-plugin/1.5/build-helper-maven-plugin-1.5.jar