gossip column

Golang binaries are a bit hard to analyze but there are some tricks to locate the things and view what is doing the code.

Is possible to list all the go files compiled in the binary even in an striped binaries, in this case we have only one file gohello.go this is a good clue to guess what is doing the program.

On stripped binaries the runtime functions are not resolved so is more difficult to locate the user algorithms:

If we start from the entry point, we will found this mess:

The golang string initialization are encoded and is not displayed on the strings window.

How to locate main? if its not stripped just bp on [package name].main for example bp main.main, (you can locate the package-name searching strings with ".main")

And here is our main.main:

The code is:

So in a stripped binary we cant find the string "hello world" neither the initialization 0x1337 nor the comparator 0x1337, all this is obfuscated.

The initialization sequence is:

The procedure for locating main.main in stripped binaries is:

1. Click on the entry point and locate the runtime.mainPC pointer:

2. click on runtime.main function (LAB_0042B030):

3. locate the main.main call after the zero ifs:

4. click on it and here is the main:

The runtime is not obvious for example the fmt.Scanf() call perform several internal calls until reach the syscall, and in a stripped binary there are no function names.

In order to identify the functions one option is compile another binary with symbols and make function fingerprinting.

In Ghidra we have the script golang_renamer.py which is very useful:

After applying this plugin the main looks like more clear:

This script is an example of function fingerprinting, in this case all the opcodes are included on the crc hashing:

# This script fingerprints the functions
#@author: sha0coder
#@category fingerprinting

print "Fingerprinting..."

import zlib


# loop through program functions
function = getFirstFunction()
while function is not None:
    name = str(function.getName())
    entry = function.getEntryPoint()
    body = function.getBody()
    addresses = body.getAddresses(True)

    if not addresses.hasNext():
        # empty function
        continue 

    ins = getInstructionAt(body.getMinAddress())
    opcodes = ''
    while ins and ins.getMinAddress() <= body.getMaxAddress():
        for b in ins.bytes:
            opcodes += chr(b & 0xff)
        ins = getInstructionAfter(ins)
    
    
    crchash = zlib.crc32(opcodes) & 0xffffffff

    print name, hex(crchash)


    function = getFunctionAfter(function)

Brutality's Installtion

How to use Brutality?

Examples:
Use default wordlist with 5 threads (-t 5) and hide 404 messages (–e 404) to fuzz the given URL (http://192.168.1.1/FUZZ):
python brutality.py -u 'http://192.168.1.1/FUZZ' -t 5 -e 404

Use common_pass.txt wordlist (-f ./wordlist/common_pass.txt), remove response with 6969 length (-r 6969) and proxy at 127.0.0.1:8080 (-p http://127.0.0.1:8080) to fuzz the given URL (http://192.168.1.1/brute.php?username=admin&password=FUZZ&submit=submit#):

python brutality.py -u 'http://192.168.1.1/brute.php?username=admin&password=FUZZ&submit=submit#' -f ./wordlist/common_pass.txt -r 6969 -p http://127.0.0.1:8080

ToDo List:

Smooth output.
Export file report.
Modularization.

Download Brutality

More info

Are you tired of reading endless news stories about ethical hacking and not really knowing what that means? Let's change that!

This Post is for the people that:

Have No Experience With Cybersecurity (Ethical Hacking)
Have Limited Experience.
Those That Just Can't Get A Break

OK, let's dive into the post and suggest some ways that you can get ahead in Cybersecurity.

I receive many messages on how to become a hacker. "I'm a beginner in hacking, how should I start?" or "I want to be able to hack my friend's Facebook account" are some of the more frequent queries. Hacking is a skill. And you must remember that if you want to learn hacking solely for the fun of hacking into your friend's Facebook account or email, things will not work out for you. You should decide to learn hacking because of your fascination for technology and your desire to be an expert in computer systems. Its time to change the color of your hat 😀

I've had my good share of Hats. Black, white or sometimes a blackish shade of grey. The darker it gets, the more fun you have.

If you have no experience don't worry. We ALL had to start somewhere, and we ALL needed help to get where we are today. No one is an island and no one is born with all the necessary skills. Period.OK, so you have zero experience and limited skills…my advice in this instance is that you teach yourself some absolute fundamentals.

Let's get this party started.

What is hacking?

Hacking is identifying weakness and vulnerabilities of some system and gaining access with it.

Hacker gets unauthorized access by targeting system while ethical hacker have an official permission in a lawful and legitimate manner to assess the security posture of a target system(s)

There's some types of hackers, a bit of "terminology".
White hat — ethical hacker.
Black hat — classical hacker, get unauthorized access.
Grey hat — person who gets unauthorized access but reveals the weaknesses to the company.
Script kiddie — person with no technical skills just used pre-made tools.
Hacktivist — person who hacks for some idea and leaves some messages. For example strike against copyright.

Skills required to become ethical hacker.

Curosity anf exploration
Operating System
Fundamentals of Networking

*Note this sites

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8.31.2020

Introduction To Reversing Golang Binaries

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