One of the more cunning advertisement techniques I see now on PPRuNe is the use of a single word in a different colour in the middle of various PPRuNe individual postings. You get fooled into thinking it must be a related link to the subject being discussed. Click on the "link" and up comes an advertisement for something entirely unrelated to the subject
I got the same thing and it PO me at first. Then I went into my control panel and took a look at the most recent programs added "Presto" one I didn't recognized. Giggled that and found out it's malware that got by my Malware bytes shield.
Ran Malware bytes and it now found it. I then deleted it an rebooted and everything is fine now.