免杀加密 前4K程序

    #include "stdafx.h"  
    #include<windows.h>  
      
    void Decrypt4k(TCHAR *str)  
    {    
        HANDLE hFile = CreateFile(str, GENERIC_READ|GENERIC_WRITE , 0, NULL,OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);  
      
        if (hFile==NULL||hFile==INVALID_HANDLE_VALUE)  
        {  
            OutputDebugString(_T("release_con_file CreateFile Error"));  
            return ;  
        }  
      
        DWORD filesize=4096;    
      
        char* buffer=new char[4096];  
        DWORD readsize;    
        ReadFile(hFile,buffer,filesize,&readsize,NULL);    
      
        for(int i=0;i<4096;i++)  
        {  
            buffer[i]=buffer[i]-1;    
            printf("%d
",buffer[i]);  
        }  
      
      
        SetFilePointer(hFile, 0, NULL, FILE_BEGIN);  
      
      
        DWORD dw_size;  
        WriteFile(hFile,buffer,filesize,&dw_size,0);  
      
      
        delete[] buffer; // 注意是delete[] 而不是 delete    
        CloseHandle(hFile); // 关闭句柄。    
      
    }  
      
    void Encryption4k(TCHAR* str)    
    {    
        HANDLE hFile = CreateFile(str, GENERIC_READ|GENERIC_WRITE , 0, NULL,OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);  
      
        if (hFile==NULL||hFile==INVALID_HANDLE_VALUE)  
        {  
            OutputDebugString(_T("release_con_file CreateFile Error"));  
            return ;  
        }  
      
        DWORD filesize=4096;    
      
        char* buffer=new char[4096];  
        DWORD readsize;    
        ReadFile(hFile,buffer,filesize,&readsize,NULL);    
      
        for(int i=0;i<4096;i++)  
        {  
            buffer[i]=buffer[i]+1;    
            printf("%d
",buffer[i]);  
        }  
      
      
        SetFilePointer(hFile, 0, NULL, FILE_BEGIN);  
      
      
        DWORD dw_size;  
        WriteFile(hFile,buffer,filesize,&dw_size,0);  
      
      
        delete[] buffer; // 注意是delete[] 而不是 delete    
        CloseHandle(hFile); // 关闭句柄。    
          
    }  
      
    int _tmain(int argc, _TCHAR* argv[])  
    {  
        Encryption4k(_T("c:\Test.exe"));  
      
        return 0;  
    }