system
8
This detection is actually more likely to be correct.
At the end of this js file is a function createCSS script that deobfuscates to an iframe - hence the JS:IFrame-AU [Trj]
This exploit is covered by the owner of unmaskparasites, in a blog post, but since it contains some of the script in plaintext it causes an alert within avast, so I wont post the link, but an image will do.
Scott