1 #include <windows.h>  
 2 #include <tchar.h>  
 3   
 4   
 5 **int**  main(**int**  argc, **char** * argv[])  
 6 {  
 7     STARTUPINFO si;  
 8     PROCESS_INFORMATION pi;  
 9     LPTSTR szCmdline=_tcsdup(TEXT("HelloWorld2"));  
10     
11     ZeroMemory( &si, **sizeof**(si) );  
12     si.cb = **sizeof**(si);  
13     ZeroMemory( &pi, **sizeof**(pi) );  
14     
15     // Start the child process.   
16     **if**( !CreateProcess( NULL,   // No module name (use command line)  
17         szCmdline,      // Command line  
18         NULL,           // Process handle not inheritable  
19         NULL,           // Thread handle not inheritable  
20         FALSE,          // Set handle inheritance to FALSE  
21         CREATE_SUSPENDED,              // Suspended the process, the key!  
22         NULL,           // Use parent's environment block  
23         NULL,           // Use parent's starting directory   
24         &si,            // Pointer to STARTUPINFO structure  
25         &pi )           // Pointer to PROCESS_INFORMATION structure  
26         )   
27     {  
28         printf( "CreateProcess failed (%d)./n", GetLastError() );  
29         **return**  -1;  
30     }  
31     
32     DWORD ldwOldPro = 0;  
33     **if**(!VirtualProtectEx(pi.hProcess, (**void** *)0x401000, 1, PAGE_EXECUTE_READWRITE, &ldwOldPro))  
34     {  
35         printf( "VirtualProtectEx failed (%d)./n", GetLastError() );  
36         TerminateProcess(pi.hProcess, -1);  
37         // Close process and thread handles.   
38         CloseHandle( pi.hProcess );  
39         CloseHandle( pi.hThread );  
40         **return**  -1;  
41     }  
42     
43     DWORD ldwWritten = 0;  
44     BYTE lbt = 0x6A;  
45     **if**(!WriteProcessMemory(pi.hProcess, (**void** *)0x401000, &lbt, 1, &ldwWritten))  
46     {  
47         printf( "WriteProcessMemory failed (%d)./n", GetLastError() );  
48         TerminateProcess(pi.hProcess, -1);  
49         // Close process and thread handles.   
50         CloseHandle( pi.hProcess );  
51         CloseHandle( pi.hThread );  
52         **return**  -1;  
53     }  
54     
55     **if**(!VirtualProtectEx(pi.hProcess, (**void** *)0x401000, 1, ldwOldPro, &ldwOldPro))  
56     {  
57         printf( "VirtualProtectEx failed (%d)./n", GetLastError() );  
58         TerminateProcess(pi.hProcess, -1);  
59         // Close process and thread handles.   
60         CloseHandle( pi.hProcess );  
61         CloseHandle( pi.hThread );  
62         **return**  -1;  
63     }  
64     
65     **if**(-1==ResumeThread(pi.hThread))  
66     {  
67         printf( "ResumeThread failed (%d)./n", GetLastError() );  
68         TerminateProcess(pi.hProcess, -1);  
69         // Close process and thread handles.   
70         CloseHandle( pi.hProcess );  
71         CloseHandle( pi.hThread );  
72         **return**  -1;  
73     }  
74   
75   
76   
77     // Wait until child process exits.  
78     WaitForSingleObject( pi.hProcess, INFINITE );  
79   
80     // Close process and thread handles.   
81     CloseHandle( pi.hProcess );  
82     CloseHandle( pi.hThread );  
83   
84     
85     **return**  0;  
86 }

 1 #include "windows.h"  
 2 int main(int argc, char* argv[])  
 3 {  
 4     printf("Give me a Process ID: ");  
 5   
 6     DWORD ldwPid = 0;  
 7     scanf("%d", &ldwPid);  
 8   
 9     HANDLE lhPro = OpenProcess(PROCESS_VM_OPERATION | PROCESS_VM_WRITE | PROCESS_VM_READ,  
10         FALSE, ldwPid);  
11   
12     if(lhPro == NULL)  
13     {  
14         printf( "Error Process ID(%u) or OpenProcess failed (%d)./n",ldwPid, GetLastError() );  
15         return -1;  
16     }  
17   
18     DWORD ldwOldPro = 0;  
19     if(!VirtualProtectEx(lhPro, (void*)0x401000, 1, PAGE_EXECUTE_READWRITE, &ldwOldPro))  
20     {  
21         printf( "VirtualProtectEx failed (%d)./n", GetLastError() );  
22         CloseHandle( lhPro );  
23         return -1;  
24     }  
25   
26     DWORD ldwReaded = 0;  
27     BYTE lbtFirst = 0;  
28     if(!ReadProcessMemory(lhPro, (void*)0x401000, &lbtFirst, 1, &ldwReaded))  
29     {  
30         printf( "ReadProcessMemory failed (%d)./n", GetLastError() );  
31         CloseHandle( lhPro );  
32         return -1;  
33     }  
34   
35   
36     DWORD ldwWritten = 0;  
37     BYTE lbt = 0xcc;  
38     if(!WriteProcessMemory(lhPro, (void*)0x401000, &lbt, 1, &ldwWritten))  
39     {  
40         printf( "WriteProcessMemory failed (%d)./n", GetLastError() );  
41         CloseHandle( lhPro );  
42         return -1;  
43     }  
44   
45     printf( "First BYTE Changed to CC,and origin first BYTE is %X./n", lbtFirst);  
46   
47     if(!VirtualProtectEx(lhPro, (void*)0x401000, 1, ldwOldPro, &ldwOldPro))  
48     {  
49         printf( "VirtualProtectEx failed (%d)./n", GetLastError() );  
50         CloseHandle( lhPro );  
51         return -1;  
52     }  
53     // Close process handles.   
54     CloseHandle( lhPro );  
55   
56   
57     
58     return 0;  
59 }