While analyzing my site I found many requests is done to external link to "friendsit.net" so I installed string locator plugin and tried to search all source files but I found nothing , I also tried to search the database but I found many results like this in select queries
how to find this link and remove ?
The external link to an image in the above site but does not exists !!
Did you try a search from the Posts (Admin) screen? (And also the Pages (Admin) screen?
And sometimes a googles of your site might find it: use something like
...depends on how current the googles are for your site. But sometimes works well.