Problem
Kaspersky Internet Security blocks ISC single-page express checkout in Step 3 after choosing a shipping method for URL /remote.php via an AJAX call.



Cause
It is a common false positive detection in Kaspersky Internet Security
Solution
Report to Kaspersky via below 4 channels. You should receive their response within 1 or 2 days
- Email: newvirus@kaspersky.com (most effective)
- Support Ticket: https://my.kaspersky.com/techsupport#/requests/
- Facebook Messenger: https://www.facebook.com/Kaspersky/
- VirusDesk: https://virusdesk.kaspersky.com/

Reference
- https://forum.kaspersky.com/index.php?/topic/304311-kaspersky-blocking-checkout-on-magento/
- https://forum.kaspersky.com/index.php?/topic/400997-false-positive-on-checkout-threat-of-data-loss-how-to-submit/
- https://community.magento.com/t5/Magento-1-x-Technical-Issues/Magento-and-Kaspersky/td-p/12129
- https://magento.stackexchange.com/questions/40757/kaspersky-false-positive-in-onepage-checkout-magento-1-9-ce
- https://magento.stackexchange.com/questions/99051/dangerous-url-blocked-on-magento-checkout-by-kapersky-internet-security-scanner
- ttps://forum.kaspersky.com/index.php?/topic/397855-2-legit-sites-blocked-threat-of-data-loss-heuristic-analysis/