avast did not block two phishing sites

Hi, why avast did not blocked two phishing site.? I did a scan and avast found two infections HTML:Phishing-TO (phish) in my directory /library/caches/com.apple.safari/webkitcache/version11/blobls then a bunch of letters and numbers. I clicked delete to delete these files. then clean my browser history and ran another scan and came clean. is my mac now safe? is it possible that these infections put a kind of script or malware on my pc to steal future info, or now I am safe. I really dont know how I could get these infections because I dont click any link from email and most of my login website are done thru previous bookmark, so where these phishing site come from? is it possible that could be a false positive?