I don't know how exhaustive the database is, but it looks like it just phones home to MS: http://news.softpedia.com/news/Windows-8-Secrets-the-Built-in-Security

I don't know how exhaustive the database is, but it looks like it just phones home to MS: http://news.softpedia.com/news/Windows-8-Secrets-the-Built-in-Security-Features-300963.shtml http://news.softpedia.com/news/Windows-8-Secrets-the-Built-i... (second screenshot). Might do the same "bloom filter plus server check for false positives" that browser malware filters use. Checking with a valid but extremely uncommon downloaded binary shows the same red banner (as well as a Chrome warning).