As the Joomla! project
the Joomla! 2.5 release branch became end-of-life with the final release of Joomla! 2.5.28 on December 10th, 2014. This means that no bugs or security issues will be fixed.
Per our policy regarding End-Of-Life Joomla! release branches, no new features will be added to 2.5 branch and our support for Joomla! 2.5 will be gradually phased out between now and December 10th, 2015. After the Joomla! 2.5 support cut-off for each software we will no longer treat Joomla! 2.5 (only issues as bugs) and we'll be providing very limited support to our Joomla! 2.5 users.
For the sites which cannot be migrated you will still be able to use old version of our software which are compatible with your Joomla! and PHP versions. Please note that these versions will not be actively supported, still get a minimal amount of support about how to use them, but do not receive bug fixes.
How to upgrade our extensions to Joomla! 3
Securitycheck (Pro) for J2.5 works only on Joomla 2.5. To complete the migration process successfully, export your Securitycheck (Pro) configuration (there is an option to do it on Securityheck Pro dashboard), uninstall Securitycheck (Pro), migrate your site to Joomla 3.x and install Securitycheck (Pro) for J3.x. After that, import previous exported configuration file and everything should be configured as on Joomla 2.5.
Securitycheck Pro Control Center and Database Update works on both branches, so you do not need to do anything special.