After the site jopran-kaffee.de has been up and running for a few months, suddenly an unexpected behaviour started to occur.
During the first visit the home page notifies about using cookies, and once the Accept button is clicked, the site redirects to random malware site. Last redirect was to https : // take-yourprizeshere1 [dot] life website. Opening of this website was blocked by antivirus (Kaspersky Internet Security in this case).
The issue only happens once after clicking the Accept button for the first time, and does not repeat again. The only way to make the issue come again is to completely wipe browser history, or to use another browser, or to use another computer. The issue would not repeat itself on the same browser again.
Customer reported no one touched the site since it was put up running in summer 2020.
I’ve checked everything, reinstalled the theme from the original theme developer files, but the issue keeps repeating on new computers/browsers. I can’t identify any other abnormalities.
Any hint where to look? Thx