On Ubuntu, by default, the hosts in .ssh/known_hosts are hashed. This can theoretically help with security. If an attacker compromises a host, they will not be able to tell the IP addresses of other hosts in the known_hosts file.
The first part ma8KL2XrNYkNnknf68N4IuZ+c+I= is the salt to use.
PmR+n2i0/epUGZZh2S+LB6OaowQ= This is our hashed IP address/hostname
ssh-ed25519 is the key type
AAAAC3NzaC1lZDI1NTE5AAAAIEjqG8/el8c669FxcvEw5mMfDRTDxsjgLiz44dCTtchs Is the public SSH key of the remote host.
SSH-KEYSCAN
We can use ssh-keyscan to check the keys of hosts. The -t ssh-ed25519 option only shows ed25519 keys. Remove or change to show all key types e.g. RSA/DSA
We can compare the SSH public key with the one in our known_hosts file to verify we have the correct host.
As a side note, we can also use the -H option to show us a hashed version. The salt changes each time it is run, so it is not useful for comparing the hashed IP address.
┌──(kali㉿localhost)-[~] └─$ history | egrep '([0-9]{1,3}\.){3}[0-9]{1,3}' | head -n2 1 ssh kali@127.0.0.1
Check if SSH Public Key is on Shodan
Since the SSH public key is um, well, public, we can search for it on Shodan to see if it’s a known public server. https://www.shodan.io
Copy the public ssh key from the known_hosts file. It is the last portion of the line i.e. AAAAC3NzaC1lZDI1NTE5AAAAIEjqG8/el8c669FxcvEw5mMfDRTDxsjgLiz44dCTtchs
Since the address space for IPv4 is fairly small, and the private IP address space even smaller, brute forcing all the addresses is perfectly feasible.
Here is a quick example on how you would hash an IP address. Commands are taken from the above Stack Exchange link.
The output is PmR+n2i0/epUGZZh2S+LB6OaowQ= which is the correct hash.
Automating should be fairly simple.
A note on SSH ports. If the host is using a non standard ssh port, you will need to update the above command with the port, but the address needs to be wrapped in square brackets []
A final way we can discover known-hosts, is by using ssh-keyscan. The man page says the following
ssh-keyscan is a utility for gathering the public SSH host keys of a number of hosts. It was designed to aid in building and verifying ssh_known_hosts files
ssh-keyscan uses non-blocking socket I/O to contact as many hosts as possible in parallel, so it is very efficient. The keys from a domain of 1,000 hosts can be collected in tens of seconds, even when some of those hosts are down or do not run sshd(8). For scanning, one does not need login access to the machines that are being scanned, nor does the scanning process involve any encryption.
Hosts to be scanned may be specified by hostname, address or by CIDR network range (e.g. 192.168.16/28). If a network range is specified, then all addresses in that range will be scanned.
This makes it super convenient to do a network scan using ssh-keyscan and then compare the public ssh keys with those in the known_hosts file.
Example:
ssh-keyscan 192.168.0.0/16
To scan all private IP ranges (RFC1912), we just run the scan with all three IP ranges
Disclaimer. Okay, we are not actually going to “hack” your bank account. But we are going to quickly use the developer tools to manipulate text on our browser.
Log into your bank account.
Find your bank and the current amount.
Open up the Developer Tools ( Menu Option > More tools > Web Developer Tools
In the top left of the developer window, select the mouse. This should let you go to the web page, click on your “account balance”.
Double click and change your “account balance” to $1 Million.
Congratulations! You are a millionaire. At least on paper.
*If you honestly were looking for a way to hack your bank account for 1 million dollars… Stop…
Quick Summary: Operation Triangulation is an iOS zero-click exploit that will self destruct, looks to have been used since at least 2019, works on iOS 15.7, unsure if it works on iOS 16. Can collect location, mic recordings, photos, and manipulate iMessages. First point of entry is from an iMessage message, that compromises the device, after compromise, the message gets deleted.
The following is a list of C&C domains from the securelist.com article. Did a quick DNS lookup for each domain and they currently have the following records & IP addresses. Note that these can change at any time and some of the IP addresses are/can be shared with other legitimate websites if it is on a shared hosting provider.
It appears that NVIDIA has limited the number of NVEncoding streams on consumer GPUs. Guess it is so people have to buy the more expensive professional cards.
Fortunately, the limit is only applied to the driver, and there is a patch available that let’s us bypass the limiter.
Ran across an email that had an attachment named Payment.htm. This kind of phishing attack isn’t anything new, but the htm file had some interesting obfuscation inside of it.
Opening up the file in a virtual a Kali virtual machine, starts to load what appears to look like a Microsoft Sharepoint site. Notice the URL is the local file. It’s setup to pull the photos from the web. Since the VM had no internet available, the images never loaded.
After spinning around for a second, it loads the “log on page”, already populated with our email address. Note I changed the email address before taking the screenshot.
Typing in a random password and hitting Sign in triggers the sign in page.
Notice the ipinfo.io network connection
Going to https://ipinfo.io/json gives us a good bit of info about our IP address, location etc. It looks like this information is requested and then sent to the hackers.
Since there was not an internet connection, the malicious htm web page never received the IP information and so didn’t continue on to the next stage, it just sat there loading. Should be able to setup a fake local server and feed it the information to continue on to the next stage. Or we can just do some static code analysis
Base64, Base64 and more Base64
Opening up the file in a text editor shows tons of Base64 encoded data. The file is only about 20 lines long, but the individual lines are super long.
This first section of Base64 encoded data is by far the shortest. atob is a javascript function that decodes Base64 data. There are multiple atob functions, meaning that to actually get the data, we’ll need to decode the data multiple times. Or we can just copy out the atob functions, and run them directly in Node.js to get the output.
This is fairly easy to do, run nodejs from the command line, set the variable, and print it to console
# nodejs
> let b64 = atob(atob(etc...etc...etc...))
> console.log(b64)
Unfortunately, the next few lines are too large to do what we just did. What we can do is duplicate the file, then delete all non javascript text. Next we can replace the beginning lines where it says “document.head……atob” to
console.log(atob(atob(atob(.....))));
After we have cleaned up the file and made those changes, we save it, and now run it as a javascript file.
nodejs ./Payment.htm
If we want to, we can pipe the output into another file with the > operator
nodejs ./Payment.htm > Decoded_Payment.js
Deobfuscating the important stuff
Looking at the decoded code shows that there is still some obfuscated stuff in that last line.
The var _0x8378= array contains a lot of human unreadable text.
Fortunately, this is not hard to decode at all. In a terminal, launch nodejs again, copy the whole array as a variable, and then just print the whole array.
The last URL is the ipinfo.io one we saw in the browser developer tools. Some of the variables from the above variable also seem to map to the return info from ipinfo.
atob() is a javascript function that decodes base64 encoded text. btoa() is the encoding function. We can use NodeJS to dedcode atob() functions. For instance, we can lanch nodejs woth
nodejs
and decode the sting SGVsbG8gV29ybGQgIQ==
console.log(atob("SGVsbG8gV29ybGQgIQ=="));
If we wanted to break that down into a couple variables we can do something like the following.
> var b64 = atob("SGVsbG8gV29ybGQgIQ==")
> console.log(b64");
You can also create a javascript file and then run the file with nodejs.
var b64 = atob(atob("U0dWc2JHOGdWMjl5YkdRZ0lRPT0="))
console.log(b64);
We can then run the file with
nodejs ./file.js
In the file the string “Hello World !” is double encoded so we process it twice with the “atob(atob(base64);”
There is more info available at the following links
Getting around applications that strip directory traversal sequences
Using a null byte
Directory Traversal
What exactly is directory traversal anyway? Well, it is pretty much exactly what it sounds like. We traverse directories by manipulate the file path, for something like an image, to get something more valuable like the passwd file.
In it’s most basic form, we can add ../../../../../etc/passwd to a file path and instead of pulling an image, we get the passwd file.
For instance, if we load an image on a website, it’s file path on the server may be something like /var/www/html/image.png. If we right click on an image and open in a new tab and inspect the URL, we can see this path. “Note: Web servers have a root directory for all the website files. Generally web files’ root starts there not / root of the machine.”
Now if we remove image.png and replace it with ../ (../ on Linux/macOS or ..\ on Windows) we’ll go backwards one directory. String them together and we can go back to the root of the drive. Then we can add /etc/passwd (Or replace with whatever file we want) and load the contents of that file.
Most web applications should have some sort of protections in place to guard against directory traversal. Let’s go over a few ways to get around it.
URL Encoding
URL encoding sometimes can work and is simple to do. In Burp, select the file path, right click, Convert selection -> URL -> URL-encode all characters.
You can also try double encoding. Encode once, select the encoded text and encode again.
In the above screenshots, ../../etc/passwd becomes “%25%32%65%25%32%65%25%32%66%25%32%65%25%32%65%25%32%66%25%36%35%25%37%34%25%36%33%25%32%66%25%37%30%25%36%31%25%37%33%25%37%33%25%37%37%25%36%34”
Getting around applications that strip directory traversal sequences
Sometimes the web app can strip out text that it knows is directory traversal characters/sequences. For instance, it sees ../ in the requested url and just strips it out.
We can do something like the following sequence to get around it.
....//....//etc/passwd
That is 4 periods, followed by 2 slashes. What happens is the web app reads the URL, goes hey ../ is not allowed, bye bye! Removes the two instances of ../ and forwards the URL on. Which ends up being
../../etc/passwd
Which is just perfect for our use case.
Using a Null Byte
If the application is using the file extension to validate that an image or other file is loaded, instead of say passwd, we can try using a null byte. A null byte is used to terminate a string.
../../etc/passwd%00.png
What can end up happening is the web application sees the .png or .jpg at the end and goes “oh that is a valid extension, carry on” and then the system reads the line and sees the null byte and says “Oh null byte! end of file path, here is your file.”
[VERBOSE] Disabled child 2 because of too many errors [VERBOSE] Disabled child 6 because of too many errors [ERROR] could not connect to target port 22: Socket error: Connection reset by peer [ERROR] could not connect to target port 22: Socket error: Connection reset by peer [ERROR] could not connect to target port 22: Socket error: Connection reset by peer [ERROR] could not connect to target port 22: Socket error: Connection reset by peer [ERROR] ssh protocol error
Looks like the issue can happen if you have too many threads going at once. Lower the amount of threads your using with -t. Recommended amount for ssh is 4.
