I have to apologise for a problem that my website has been causing. I found that it has been infected with some form of malware that resulted in a spurious window opening whenever anyone clicked on a link to a page or another post. This window contained spam content of various kinds. The originator of the malware was apparently getting paid for each click that occurred
It’s taken me about eight hours of work today to discover the cause of the problem – one of the plug-ins that operates on my site. This has now been replaced with an authentic one and the problem has been fixed.
I am sorry for the inconvenience that this might have caused to anyone.