Normal browsing behavior, with non-MS (ie *not* Edge or IE) product, results in recurrent browser cache occurrence of variants of this apparently common, apparently MS-targeting mal-code. This is regularly discovered with another vendor's antivirus package.
No clear documentation on any *generic* threat from this code has been discovered; only reference to its leveraging an IE (&/or Edge?) vulnerability.
My interests include the desire to identify injection source as well as nature of threat; is it possible for Avast family (incl. AVG) to include this recognition on-the-fly?
BTW, unrelated, here's a just-recognized threat location :
