I have a very strange problem on the website of a client of mine.

It's a wordpress website I have designed with a child theme of the Leisure theme. I have coded a couple of simple plugins to suit the needs of the client and we use some commercial and some free wordpress plugins.

Everything is running absolutely fine with no errors. But there's one huge thing:

On a few clients it seems that the telephone number +41 41 392 27 XX (i've blanked out the last 2 digits) changes automatically to +041 561 52 28 . This number has absolutely nothing to do with their telephone number except that +041 sort of. And it's not even a valid phone number I think? Sometimes it appears in the footer instead of the real number, sometimes in the body of the site.

I have never been able to recreate the problem on my Windows or OSX machines.

To circumvent the problem I have now written a little plugin that loads the phone number at the very end of the loading process via shortcode and javascript:


add_shortcode( 'oz_phone', 'oz_phone' );
function oz_phone() {
    return '<span class="telnroz"></span>';

add_action( 'wp_footer', 'oz_footer_scripts' );
function oz_footer_scripts(){
jQuery(window).on('load', function() {

    jQuery(".telnroz").html('Telefon <a href="tel:+414139227XX">+41 41 392 27 XX</a>');


But the problem is STILL OCCURRING! I'm going crazy here! What's this? Maybe some sort of virus on the client side?

Since I can't recreate the problem, I can't just test it with disabling some plugins. I am totally 100% stuck.

Maybe some of you might have some clues I could follow up on?

Every input from you ppl is MUCH appreciated! thanks

  • The only time I've seen numbers change are due to call tracking scripts added that swap them out, but if you designed the site I'm sure you are aware of what scripts are running.
    – Rob T
    Oct 23 '19 at 18:21
  • 4
    "I have never been able to recreate the problem on my Windows or OSX machines. .... I can't recreate the problem" - This sounds like a (rogue) browser plugin (or virus - as you say) at the client end. If it was a problem with your website/WordPress then this would be repeatable. Test on as many browsers/machines/devices as your can. "On a few clients" - how widespread is this problem? More than one client - more than one website? Or are you referring to "client" as in client/server?
    – DocRoot
    Oct 23 '19 at 21:02
  • Thanks for your inputs. The website has about 150 individual users per day. We've had 4 reports of users so far. However, it's basically "a good deed" when they tell us that the phone number's not working. They could very well also just ignore it. So my guess is the real number is between 10 and 50 occurences. it's just on one website Oct 24 '19 at 9:50
  • The first two uses of client i mean the website, but in the paragraph where I describe the problem (on a few clients), I mean the actual computer (client as in client/server) Oct 24 '19 at 9:51
  • "4 reports of users ... real number is between 10 and 50 occurences. it's just on one website" - Do you know the browser/device they were using? Hhmm, with that number of reports and just the one website affected, it's looking more like an issue with the website?! (Unless this is a very common (rogue) browser plugin?!) To clarify, your "JavaScript plugin" to try and resolve the problem does not resolve the problem? My only thought to try and "workaround" the issue is to remove the tel: protocol from the link, since that may also be what other (browser) plugins are using to find tel nos?
    – DocRoot
    Oct 24 '19 at 14:15