Supposedly the Junk filter is supposed to help remove the bad files. However, the Junk filter is a dynamic learning filter, you need to train it so it knows the good from the bad files.

Unfortunately yes, there is a lot of spam on the network, and learning some basic skills to recognise what is genuine & what is spam is needed. At least with the sample images in one of those links, it gives some clues. Such as ignoring audio files that show no audio bitrate or are smaller than a particular size. You can use LW's filters to filter the search results by size. Most audio songs are between 1-10 MB depending on their length & Bitrate. The higher the bitrate & song length, the larger the file size will be. Make sure you set your LW window up to show bit-rate. Song files with no bit-rate will most likely be fake (viruses or such.)

Example: a 3 minute song encoded at 320 kbps is going to have a larger file size than the same song encoded at 128 kbps.