ummy.netは安全ですか？

See comments for the subdomain that delivers the payload: https://www.mywot.com/en/scorecard/videodownloader.ummy.net My experience was somewhat better than eugenikus8's: ***** shows suspicious activity, but no AV hits. Suspicious activity (my interpretation) reported by virustotal included: Writing to Library/Preferences/com.apple.security.sts.plist Messing with Keychain (which contains security-critical stuff - certs, passwords, etc.), Address Book, files including Keychains/EVRoots.plist, /Library/Keychains/System.keychain,...