/usr/share/icingaweb2/modules/monitoring/application/views/helpers/ is in icingaweb2-module-monitoring 2.1.0-1ubuntu1.
This file is owned by root:root, with mode 0o755.
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/usr/share/icingaweb2/modules/monitoring/application/views/helpers/CheckPerformance.php
/usr/share/icingaweb2/modules/monitoring/application/views/helpers/ContactFlags.php
/usr/share/icingaweb2/modules/monitoring/application/views/helpers/Customvar.php
/usr/share/icingaweb2/modules/monitoring/application/views/helpers/HostFlags.php
/usr/share/icingaweb2/modules/monitoring/application/views/helpers/IconImage.php
/usr/share/icingaweb2/modules/monitoring/application/views/helpers/Link.php
/usr/share/icingaweb2/modules/monitoring/application/views/helpers/MonitoringFlags.php
/usr/share/icingaweb2/modules/monitoring/application/views/helpers/Perfdata.php
/usr/share/icingaweb2/modules/monitoring/application/views/helpers/PluginOutput.php
/usr/share/icingaweb2/modules/monitoring/application/views/helpers/RuntimeVariables.php
/usr/share/icingaweb2/modules/monitoring/application/views/helpers/ServiceFlags.php