Probably something that was scripted for that specific purpose (by someone with a Solaris background)? It's not uncommon for scripts to get triggered by the presence of a certain file in a certain place at boot time. Look in the start-up directories and files (/etc/rc.conf.local, /etc/rc.local, /etc/rc.d/, /usr/local/etc/rc.d/, crontab, and thereabouts) for a script.