Is it me or are spammers recruiting more script kiddies as of late? Not much of a big deal considering their numbers are on the rise...*ahem* anonymous *ahem*.
Chris. On Wed, Apr 13, 2011 at 4:47 PM, Cal Leeming <[email protected]> wrote: > Well, the problem was the person(s) running the bots kept bypassing the > simple protections such as these. Although it isn't 100% fool proof, it does > make things *extremely* difficult for the person(s) with the bots, so much > so, that they usually give up, unless they have specifically targeted you > for some reason. > > So, instead we created hundreds of these little JS chunks, all with > different lookup tables applied, and cycled them on an hourly basis. It > meant if they wanted to continuously bot the service, they would have to de > obfuscate the protection code, or find a mathmatical/bruteforce attack that > would generate the seedkey for them. It would either involve manual > intervention or code modification on the bot to make it work.. I'd > have preferred to have added captcha, but there was a reasonable explanation > as to why the client didn't want it. > > Either way, once we put this in, they gave up pretty quickly lol. > > > On Wed, Apr 13, 2011 at 3:29 PM, Christian Sciberras <[email protected]>wrote: > >> Cal /Ryan, >> >> I'm not sure what you're trying to achieve. >> If we're talking about absolutely stupid bots, the following easily >> defeats them: >> <form> >> <stuff/> >> <script type=text/javascript>document.write('<input type="hidden" >> name="access" value="code"/>');</script> >> <form> >> >> I suppose you could obfuscate it all if you wanted to cater for script >> kiddies. >> But considering this is very weak protection (as opposed to proper >> captcha), I'm not sure if it's even worthwhile. >> One of the ways I can see this work is against automated, "JS-ignorant", >> MITM systems. >> >> As indeed is true, you should never trust the end user. >> But in a MITM scenario, the user we're not trusting is the one conducting >> the attack, not the other. >> >> Chris. >> >> >> >> On Wed, Apr 13, 2011 at 1:07 PM, Cal Leeming <[email protected]>wrote: >> >>> Lol, I've just realised something.. I didn't include the seed key >>> variable itself, so this code would have been pretty much useless on it own >>> *DOH*. >>> >>> So, here's something else a bit tasty.. this is the server side code used >>> to check and create the seedkey itself (secret lookup table has been changed >>> obv.). >>> >>> This code allows seedkeys to be generated from epoch time. Now, >>> cryptographically I don't know how "sane" this is, but I'm fairly sure that >>> if the lookup table contained large integers it would become almost >>> impossible to do a pattern based brute force. I actually had quite a lot of >>> fun trying to break my own code. :D >>> >>> PS) you have been awarded 1 internets. >>> >>> >>> function get_valid_keys() { >>> // Create key store >>> $_s = array(); >>> >>> // Create valid key ranges (+900 seconds) >>> for($x=300;$x>=900;$x+=300): >>> $_s[] = $this->create_key($offset=$x); >>> endfor; >>> >>> // Create valid key ranges (-900 seconds) >>> for($x=300;$x>=-900;$x-=300): >>> $_s[] = $this->create_key($offset=$x); >>> endfor; >>> >>> $_s[] = $this->create_key(); >>> >>> return $_s; >>> } >>> >>> function create_packed_key() { >>> // Create a new valid key >>> $key = $this->create_key(); >>> >>> // Now generate the packed key >>> $k = array(); >>> // Now convert it into an array >>> for($x=0;$x<strlen($key);$x++): >>> $_v = unpack("H*", $key[$x]); >>> $k[]='\x'.$_v[1]; >>> endfor; >>> >>> // Okay, here is your brand new shiney key, sir :) >>> $m = '"'.implode('","', $k).'"'; >>> $m = strrev($m); >>> $_m = array(); >>> for($x=0;$x<strlen($m);$x++): >>> $_m[]=$m[$x]; >>> endfor; >>> return json_encode(implode("ZPAK", $_m)); >>> } >>> >>> function create_key($offset=0) { >>> // Secret key table, used to mix up the seed >>> $enc = array( >>> 0 => "67892", >>> 1 => "3953", >>> 2 => "49474", >>> 3 => "494755", >>> 4 => "30585", >>> 5 => "30582", >>> 6 => "20485", >>> 7 => "20486", >>> 8 => "97294", >>> 9 => "10284" >>> ); >>> >>> // Generate new seed >>> $time = time(); >>> if ($offset): >>> $time=$time+$offset; >>> endif; >>> $c=(int)($time/$this->_security_key_refresh); >>> $_c = "$c"; >>> >>> // Extract the last 5 digits of the number >>> $char1 = substr($_c, strlen($c)-1, 1); >>> $char2 = substr($_c, strlen($c)-2, 1); >>> $char3 = substr($_c, strlen($c)-3, 1); >>> $char4 = substr($_c, strlen($c)-4, 1); >>> $char5 = substr($_c, strlen($c)-5, 1); >>> >>> // Lookup the modifier from the secret key table >>> $mt1 = $enc[$char1]; >>> $mt2 = $enc[$char2]; >>> $mt3 = $enc[$char3]; >>> $mt4 = $enc[$char4]; >>> $mt5 = $enc[$char5]; >>> >>> // Generate a new key, based on the modifiers >>> $key = round((($c+$mt1) + ($c+$mt2) + ($c+$mt3) + ($c+$mt4) + >>> ($c+$mt5))/256); >>> $key = "$key"; >>> return $key; >>> } >>> >>> >>> >>> >>> >>> On Wed, Apr 13, 2011 at 3:56 AM, Ryan Sears <[email protected]> wrote: >>> >>>> Me thinks I may have it right (mostly)... >>>> >>>> It seems to be some jquery to append a hidden input element to the >>>> "theform" id (presumably a form on the page ;) ) called "seedkey", and has >>>> a >>>> value of whatever t is evaluated to (which I'm still stuck on as I don't >>>> know jquery much at all, so I can't figure out the s[] array, but I know it >>>> has something to do with the bracket notation...). >>>> >>>> ================================================= >>>> += Orig =+ >>>> $(function () { >>>> var _0xafd3 = ["\x74\x20\x3D\x20\x22", "", "\x6A\x6F\x69\x6E", >>>> "\x72\x65\x76\x65\x72\x73\x65", "\x73\x70\x6C\x69\x74", >>>> "\x72\x65\x70\x6C\x61\x63\x65", "\x22"]; >>>> >>>> eval(_0xafd3[0] + s[_0xafd3[5]](/ZPAK/gi, >>>> _0xafd3[1])[_0xafd3[5]](/\",\"/gi, _0xafd3[1])[_0xafd3[5]](/\"/gi, >>>> _0xafd3[1])[_0xafd3[4]](_0xafd3[1])[_0xafd3[3]]()[_0xafd3[2]](_0xafd3[1]) + >>>> _0xafd3[6]); >>>> var _0x5bfa = ["\x3C\x69\x6E\x70\x75\x74\x20\x2F\x3E", >>>> "\x74\x79\x70\x65", "\x68\x69\x64\x64\x65\x6E", "\x61\x74\x74\x72", >>>> "\x6E\x61\x6D\x65", "\x73\x65\x65\x64\x6B\x65\x79", "\x76\x61\x6C\x75\x65", >>>> "\x61\x70\x70\x65\x6E\x64", "\x23\x74\x68\x65\x66\x6F\x72\x6D"]; >>>> _n = $(_0x5bfa[0]); >>>> _n[_0x5bfa[3]](_0x5bfa[1], _0x5bfa[2]); >>>> _n[_0x5bfa[3]](_0x5bfa[4], _0x5bfa[5]); >>>> _n[_0x5bfa[3]](_0x5bfa[6], t); >>>> $(_0x5bfa[8])[_0x5bfa[7]](_n); >>>> }); >>>> >>>> += De-obfuscated =+ >>>> $(function () { >>>> var _0xafd3 = ['t = "', '', 'join', 'reverse', 'split', >>>> 'replace', '"']; >>>> var _0x5bfa = ['<input />', 'type', 'hidden', 'attr', 'name', >>>> 'seedkey', 'value', 'append', '#theform']; >>>> >>>> eval('t = "' + s['replace'](/ZPAK/gi, '')['replace'](/\",\"/gi, >>>> '')['replace'](/\"/gi, '')['split']('')['reverse']()['join']('') + '"'); >>>> >>>> _n = $('<input />'); >>>> _n['attr']('type', 'hidden'); >>>> _n['attr']('name', 'seedkey'); >>>> _n['attr']('value', t); >>>> $('#theform')['append'](_n); >>>> }); >>>> >>>> ================================================= >>>> >>>> Fun stuffs. I can haz a internetz? :-P >>>> >>>> Ryan >>>> >>>> >>>> ----- Original Message ----- >>>> From: "Cal Leeming" <[email protected]> >>>> To: [email protected] >>>> Sent: Tuesday, April 12, 2011 5:28:22 PM GMT -05:00 US/Canada Eastern >>>> Subject: [Full-disclosure] guess what this does.. >>>> >>>> $(function() { >>>> var >>>> >>>> _0xafd3=["\x74\x20\x3D\x20\x22","","\x6A\x6F\x69\x6E","\x72\x65\x76\x65\x72\x73\x65","\x73\x70\x6C\x69\x74","\x72\x65\x70\x6C\x61\x63\x65","\x22"];eval(_0xafd3[0]+s[_0xafd3[5]](/ZPAK/gi,_0xafd3[1])[_0xafd3[5]](/\",\"/gi,_0xafd3[1])[_0xafd3[5]](/\"/gi,_0xafd3[1])[_0xafd3[4]](_0xafd3[1])[_0xafd3[3]]()[_0xafd3[2]](_0xafd3[1])+_0xafd3[6]); >>>> var >>>> >>>> _0x5bfa=["\x3C\x69\x6E\x70\x75\x74\x20\x2F\x3E","\x74\x79\x70\x65","\x68\x69\x64\x64\x65\x6E","\x61\x74\x74\x72","\x6E\x61\x6D\x65","\x73\x65\x65\x64\x6B\x65\x79","\x76\x61\x6C\x75\x65","\x61\x70\x70\x65\x6E\x64","\x23\x74\x68\x65\x66\x6F\x72\x6D"];_n=$(_0x5bfa[0]);_n[_0x5bfa[3]](_0x5bfa[1],_0x5bfa[2]);_n[_0x5bfa[3]](_0x5bfa[4],_0x5bfa[5]);_n[_0x5bfa[3]](_0x5bfa[6],t);$(_0x5bfa[8])[_0x5bfa[7]](_n); >>>> }); >>>> >>>> enjoy ;p >>>> >>>> ps) yes I obfuscated this, and no it doesn't contain any nasties. >>>> >>>> _______________________________________________ >>>> Full-Disclosure - We believe in it. >>>> Charter: http://lists.grok.org.uk/full-disclosure-charter.html >>>> Hosted and sponsored by Secunia - http://secunia.com/ >>>> >>> >>> >>> _______________________________________________ >>> Full-Disclosure - We believe in it. >>> Charter: http://lists.grok.org.uk/full-disclosure-charter.html >>> Hosted and sponsored by Secunia - http://secunia.com/ >>> >> >> >
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