What seems like a malicious email made it through the filters, broke down the attachment into this, need some help.

Hey there all, came across this bit of javascript and was wondering if anyone could help me break down what it does?

There were a few other parts to the html page I found this with. Namely a giant chunk of encoded something that is surrounded by:

DBwexeikCS = atoc(atob('

MASSIVE ENCODING (not UTF-8, 16, or 32)

'),'123');

Then a non obfuscated chunk of JS:

< script >
(function (_0x23eaff, _0x32f5f2) {
var _0x5e9573 = a0_0x3fa8,
_0x127d35 = _0x23eaff();
while …

down email malicious malware