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有一段时间没做测试了，偶尔的时候也会去挖挖洞。本文章要写的东西是我利用ClickJacking拿下管理员权限的测试过程。但在说明过程之前，先带大家了解一下ClickJacking的基本原理以及简单的漏洞挖掘。

ClickJacking背景说明:

ClickJacking（点击劫持）是由互联网安全专家罗伯特·汉森和耶利米·格劳斯曼在2008年首创的。 ClickJacking是一种视觉欺骗攻击手段，在web端就是iframe嵌套一个透明不可见的页面，让用户在不知情(被欺骗)的情况下，点击攻击者想要欺骗用户点击的位置。

说道视觉欺骗，相信有炫技经验的朋友们一定会想到，自己一个后台拿不下Webshell权限的时候，而想要黑掉首页从而达到炫技，使用的是什么呢？没错一般使用CSS样式表来劫持首页以造成黑掉的假象~

除了可以炫技，CSS劫持可以做的东西也有很多：例如经典的form表单钓鱼攻击

这里就不对代码的意思进行解读了，可以看到CSS劫持达到的视觉欺骗攻击效果还是比较LOW的，因为这样的攻击手段偏被动式。而我要说的点击劫持其实也算是被动式，不过相对来说比较容易获得信任让被动式触发，这里只是单单对攻击手法谁的成功率比较高作为比较

前面背景介绍的时候说了，点击劫持攻击其实就是镶嵌一个iframe框架(存在点击劫持漏洞的页面)在页面上，然后再把其修改为透明的样式。这样的操作只是造成了视觉欺骗，还没达到欺骗点击的效果，所以就需要知道iframe框架其按钮的位置，然后在基于透明层模拟一个位置大小相同的按钮，发给用户让其点击~~

这里以QQ安全中心的一个点击劫持为例，作为一个QQ的资深用户应该知道QQ是有安全中心紧急冻结QQ服务的，只要登录自己的安全中心就可以冻结，地址(漏洞地址，目前漏洞已经修复)为：https://aq.qq.com/cn2/message_center/wireless/wireless_seal_auth?source_id=2985

一点击，你的QQ就被会冻结(当时不知道逗了多少人~)，那这样怎么利用呢？

1.建立iframe框架:

2.建立iframe的CSS样式:

3.获取iframe框架引用的原页面的按钮位置和大小:

大小直接通过审查元素可以看得到:

现在要获取的就是按钮元素到浏览器顶部的距离，这里通过id.offsetTop有些时候是无法直接获取的:

>>span_verify.offsetTop ←16

获取到的是16~很醉，所以使用如下的方法直接获取:

4.建立按钮:

5.根据第三步骤获取到的建立按钮样式:

6.散播，用户中招:

说了这么多，在前几天的测试中我是如何拿到管理员权限呢？挖掘到一处self-xss，这里先说明下self-xss可以理解为只能攻击myself~

发现流程:

发现输入框->秉着见框就X的原理插入XSS Payload->弹框->发现成功

然而获取到的URL链接是/?keyword=<script>alert(1)</script>，但是不是xss，keyword的值显示在输入框内，需要你再点击搜索标题按钮才可以触发漏洞。

形成的攻击思路->iframe嵌套漏洞URL链接->Click Jacking攻击页面构造->通过留言给管理员引诱触发

攻击页面构造流程其实耐心读到这里的朋友已经是非常明确步骤了:

建立iframe框架->建立iframe框架CSS样式->获取按钮位置大小->建立按钮->建立按钮CSS样式->留言板留言外网攻击链接->获取管理员Cookie->Cookie伪造进入后台

一次很有意思的实践，让自己满满的成就感，同时也完成了项目任务~

Cyber threat analysis from a range of sources, including the United States and the United Kingdom, attributes WannaCry to North Korean cyber threat actors

Computers do what they are told whether good or bad. One of the best ways to detect intrusions is to recognize when computers are following bad instructions – whether in binary form or in some higher-level scripting language. We’ll talk about scripting in the future but in this article, I want to focus on monitoring execution of binaries in the form of EXEs, DLLs and device drivers.

The Windows Security Log isn’t very strong in this area. Event ID 4688 tells you when a process is started and provides the name of the EXE – in current versions of Windows you thankfully get the full path – in older versions you only got the file name itself. But even full pathname isn’t enough. This is because that’s just the name of the file; the name doesn’t say anything about the contents of the file. And that’s what matters because when we see that c:\windows\notepad.exe ran how do we know if that was really the innocent notepad.exe that comes from Microsoft? It could be a completely different program altogether replaced by an intruder, or more in more sophisticated attacks, a modified version of notepad.exe that looks and behaves like notepad but also executes other malicious code.

Instead of just the name of the file we really need a hash of its contents. A hash is a relatively short, finite length mathematical digest of the bit stream of the file. Change one or more bits of the file and you get a different hash. (Alert readers will recognize that couldn’t really be true always – but in terms of probabilistic certainty it’s more than good enough to be considered true.)

Unfortunately, the Security Log doesn’t record the hash of EXEs in Event ID 4688, and even if it did, that would only catch EXEs – what about DLLs and device drivers? The internal security teams at Microsoft recognized this need gap as well as some which apparently led to Mark Russinovich, et al, to write Sysmon. Sysmon is a small and efficient program you install on all endpoints which generates a number of important security events “missing” from the Windows Security Log. In particular, sysmon logs:

• Event Id 1 - for process creation (i.e. an EXE was started)
• Event Id 6 – driver loaded
• Event Id 7 – imaged loaded (i.e. an DLL was loaded)

Together these 3 events created a complete audit record of every binary file loaded (and likely executed) on a system where sysmon is installed.

But, in addition to covering DLLs and drivers, these events also provide the hash of the file contents at the time it was loaded. For instance, the event below shows that Chrome.exe was executed and tells us that the SHA 256-bit hash was 6055A20CF7EC81843310AD37700FF67B2CF8CDE3DCE68D54BA42934177C10B57.

   Process Create:

   UtcTime: 2017-04-28 22:08:22.025

   ProcessGuid: {a23eae89-bd56-5903-0000-0010e9d95e00}

   ProcessId: 6228

   Image: C:\Program Files (x86)\Google\Chrome\Application\chrome.exe

   CommandLine: "C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --type=utility --lang=en-US --no-sandbox --service-   request-channel-token=F47498BBA884E523FA93E623C4569B94 --mojo-platform-channel-handle=3432 /prefetch:8

   CurrentDirectory: C:\Program Files (x86)\Google\Chrome\Application\58.0.3029.81\

   User: LAB\rsmith

   LogonGuid: {a23eae89-b357-5903-0000-002005eb0700}

   LogonId: 0x7EB05

   TerminalSessionId: 1

   IntegrityLevel: Medium

   Hashes: SHA256=6055A20CF7EC81843310AD37700FF67B2CF8CDE3DCE68D54BA42934177C10B57

   ParentProcessGuid: {a23eae89-bd28-5903-0000-00102f345d00}

   ParentProcessId: 13220

   ParentImage: C:\Program Files (x86)\Google\Chrome\Application\chrome.exe

   ParentCommandLine: "C:\Program Files (x86)\Google\Chrome\Application\chrome.exe"

Now, assuming we have the ability to analyze and remember hashes, we can detect whenever a new binary runs on our network.

Sysmon allows you to create include and exclude rules to control which binaries are logged and which hashes are computed based on an xml configuration file you supply sysmon at installation time or any time after with the /c command. Sysmon is easy to install remotely using Scheduled Tasks in Group Policy’s Preferences section. In our environment we store our sysmon.xml file centrally and have our systems periodically reapply that configuration file in case it changes. Of course, be sure to carefully control permissions where you store that configuration file.

Just because you see a new hash – doesn’t necessarily mean that you’ve been hacked. Windows systems are constantly updated with Microsoft and 3rd party patches. One of the best ways to distinguish between legitimate patches and malicious file replacements is if you can regularly whitelist known programs from a systems patched early – such as patch testing systems.

Once sysmon is installed you need to collect the Sysmon event log from each endpoint and then analyze those events – detecting new software. EventTracker is a great technology for accomplishing both of these tasks.

“This article by Randy Smith was originally published by EventTracker” https://www.eventtracker.com/newsletters/report-all-the-binary-code-executing-on-your-network-with-sysmon-event-ids/

As I write this yet another ransomware attack is underway. This time it’s called Petya and it again uses SMB to spread but here’s the thing. It uses an EXE to get its work done. That’s important because there are countless ways to infect systems, with old ones being patched and new ones being discovered all the time. And you definitely want to reduce your attack surface by disabling/uninstalling unneeded features. And you want to patch systems as soon as possible. 

Those are preventive controls and they are irreplaceable in terms of defense in depth. But no layer of defense is ever a silver bullet. Patching and surface area management will never stop everything.

So we need an effective detective control that tells us as soon as something like Petya gets past our frontline preventive layers of defense. The cool thing is you can do that using nothing more than the Windows security log – or even better – Sysmon. Event ID 4688, activated by enabling Audit Process Creation for success, is a Security log event produced every time and EXE loads as a new process. 

If we simply keep a running baseline of known EXE names and compare each 4688 against that list, BAM!, you’ll know as soon as something new like Petya’s EXE’s run on your network. Of course you need to be collecting 4688s from your workstations and your SIEM needs to be able to do this kind of constant learning whitelist analysis. And you are going to get events when you install new software or patch old software. But only when new EXE names show up.

The only problem with using 4688 is it’s based on EXE name (including path). Bad guys can – but don’t usually bother to use replace known EXEs to stay below the radar. That would defeat the above scheme. So what can you do? Implement Sysmon which logs the hash of each EXE. Sysmon is a free element of Microsoft Sysinternals written by Mark Russonovich and friends. Sysmon event ID 1 (shown below) is logged the same time as 4688 (if you have both process creation auditing and Sysmon configured) but it also proves the hash of the EXE. So even if the attacker does replace a known EXE, the hash will difference, and your comparison against known hashes will fail – thus detecting a new EXE executing for the first time in your environment.

Log Name: Microsoft-Windows-Sysmon/Operational
Source: Microsoft-Windows-Sysmon
Date: 4/28/2017 3:08:22 PM
Event ID: 1
Task Category: Process Create (rule: ProcessCreate)
Level: Information
Keywords:
User: SYSTEM
Computer: rfsH.lab.local
Description:
Process Create:
UtcTime: 2017-04-28 22:08:22.025
ProcessGuid: {a23eae89-bd56-5903-0000-0010e9d95e00}
ProcessId: 6228
Image: C:\Program Files (x86)\Google\Chrome\Application\chrome.exe
CommandLine: "C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --type=utility --lang=en-US --no-sandbox --service-request-channel-token=F47498BBA884E523FA93E623C4569B94 --mojo-platform-channel-handle=3432 /prefetch:8
CurrentDirectory: C:\Program Files (x86)\Google\Chrome\Application\58.0.3029.81\
User: LAB\rsmith
LogonGuid: {a23eae89-b357-5903-0000-002005eb0700}
LogonId: 0x7EB05
TerminalSessionId: 1
IntegrityLevel: Medium
Hashes: SHA256=6055A20CF7EC81843310AD37700FF67B2CF8CDE3DCE68D54BA42934177C10B57
ParentProcessGuid: {a23eae89-bd28-5903-0000-00102f345d00}
ParentProcessId: 13220
ParentImage: C:\Program Files (x86)\Google\Chrome\Application\chrome.exe
ParentCommandLine: "C:\Program Files (x86)\Google\Chrome\Application\chrome.exe"  

Tracking by hash will generate more false positives because anytime a known EXE is updated by the vendor, the first time the new version runs, a new hash will be generated and trip a new alarm or entry on your dashboard. But this tells you that patches are rolling out and confirms that your detection is working. And you are only notified the first time the EXE runs provided you automatically add new hashes to your whitelist. 

Whether you track new EXEs in your environment by name using the Security Log or by hash using Sysmon – do it! New process tracking is one of those highly effective, reliable and long lived, strategic controls that will alert you against other attacks that rely on EXE still beyond the horizon.

“This article by Randy Smith was originally published by EventTracker” https://www.eventtracker.com/newsletters/yet-another-ransomware-that-can-be-immediately-detected-with-process-tracking-on-workstations/

The Domain Name System (DNS), if not properly secured, may be susceptible to abuse by malicious actors. Cybercriminals recognize the value of DNS availability and look for ways to compromise DNS uptime and the DNS servers that support it. As such, DNS becomes an important point of security enforcement and a potential point in the […]

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