What is FLVto?
FLVto lets you download YouTube videos by URL and convert them into other formats such as mp3, avi and mp4. It can download multiple files simultaneously and has a built-in audio player and ID3 tag editor for music.
Site opens malicious pop-ups and downloads may contain adware. See https://www.virustotal.com/en/file/e9341a279b71d9d42eab45bd5e84da86bd40791e31147922a1bf9f46a1fc01a5/analysis/