If you don't want to upgrade to new Osclass 3.9.0, you can use use this guide to remove Osclass Market from your current installation.
This guide was made by webmods-croatia and was originally posted on docs.osclasscommunity.com which is now moved here.
This guide covers most, if not all, changes required to un-tie your site from Osclass Market
If you know some changes that we forgot, post it on our forums or contact us via the links above.
As a test if this mods were successful, we put error_log('cURL:'.$url);
in osc_file_get_contents()
function.
We visited admin homepage, plugins, themes and language pages, settings page, we checked for updates, we ran cron, etc.
There wasn't a single cURL log that says that a request has been made to Osclass.
Also, all this changes were made on a live site as the guide was written. There were no problems, errors and warnings.