[C++] HostsPatch

[SLV]

a few recomendations..

> GetWindowsDirectoryA(hosts, 256);
> PathAppendA(hosts, "system32\\drivers\\etc\\hosts");
using a symlink \\.\globalroot\systemroot\drivers\hosts will be more easy

> char* data=new char[size+website_len*2];
ok, new, c++, but it generate an exception if can't alloc memory. no try/except found.

> int website_len=strlen(website);
no input buffer check.

> memset(data, 0, size+website_len*2);
by default new memory is alreadt zero initiialized.

> if(!ReadFile(hFile, data, size, &read, 0))
if(!ReadFile(hFile, data, size, &read, 0) || read != size)

> MessageBoxA(hwndDlg, "Could not read file attributes", "Opened with admin privileges?", MB_ICONERROR|MB_SYSTEMMODAL);
use IsUserAnAdmin for checking admin rights, GetFileAttributes doesn't require them.

> unsigned int size=GetFileSize(hFile, 0);
it's recommended to use GetFileSizeEx

> if(!WriteFile(hFile, data, strlen(data), &written, 0))
if(!WriteFile(hFile, data, strlen(data), &written, 0) || strlen(data) != written)

I advice you to read about SESE coding style.
In general such code is not recommended to use because hosts is a malwares lovely file. It's better to use firewall or hooks.