In the context of scams like this on a web page (as opposed to scams like this being performed by malicious browser extensions or malicious software) as shown in the second image on post#4, these sort of pop-ups and messages can be prevented by running NoScript. I haven't seen a single "your computer is infected" scam pop-up or "the web page at example.com says:" dialog box since I installed Noscript, before then they were appearing all over the place, sometimes on large and extremely legitimate sites (like news sites)because the pop-up or dialog box was generated by an advert on the page. I recognised them especially because they said things like "your java plugin is out of date", when I knew I didn't have java installed at all.
Post #9: "Here's hoping that the writers stay dumb"
They do it deliberately. Just like email scammers they deliberately make spelling mistakes and associate themselves with well known scamming locations, organsiations and techniques because this lets them filter out the half-suspicous people before they have to put in more effort in the next stage of a scam. Notice how many scam emails actually start with the sentence "I am from [location often associated with scams] and contacting you for [reason which most would find very hard to believe]..." . Basically by making "spelin miztaks" they can ensure anyone who might believe a legitimate looking prompt/email/pop-up but then realise it's true nature when it came to the phonecall or reply email is filtered out, they ensure only the most vulnerable will respond by making mistakes to scare off everyone else. This is because it takes almost no effort for the scammers to spread the original pop-up/dialog/email/prompt but some effort for scammers to convince people on the phone, or in a reply email, that they are genuine. So the scammers don't mind only a tiny proportion of the people seeing the original pop-up/email/prompt beleiving it but would like to make sure all those who do are already at the stage of being fully tricked into believing all the subsequent stages of the scam. "Speeling and gramur" mistakes are a tactic used by scammers to narrow their targeting of vulnerable prey.
Edited by rp88, 23 May 2015 - 04:12 PM.
Back on this site, for a while anyway, been so busy the last year.
My systems:2 laptops, intel i3 processors, windows 8.1 installed on the hard-drive and linux mint 17.3 MATE installed to USB