You should be aware of possible alerts of the avast shields whenever you go to visit a site where there is live malware, links to live malware or part of malcious code (even when it is without a payload and so harmless). That is also the reason why we break links or present code in the form of an image.
Whenever you use online sites to “sniff” html code use a script blocker and open up sandboxed. As a general rule those that aren’t that security savvy and not aware of the risks of “live” malcode" better stay away or use “cold reconnaissance or third party scanning tools”. Curiosity killed the “proverbial animal”,