Netcat

Netcat is the swiss army knife of the hackers. Netcat is used for file (exploit) transfer, finding open ports & remote administration (Bind & Reverse Shells). You can manually connect to any network service like HTTP using netcat. Another utility is to listen on any UDP/TCP ports on your machine for any incoming connections.

• Windows: ncat.exe
• Linux:
  • nc (netcat-openbsd package)
  • ncat (nmap package)

nc examples

• echo "text to send" | nc IP port
• echo "text to send" | nc 10.10.10.10 54

• Forward port (see also socat):

nc -l -p ORIGIN_PORT -c 'nc DESTINATION_IP DESTINATIO_PORT'

nc -l -p 2222 -c 'nc 10.10.10.4 8888'

<nc<IPaddress or FQDN> <port number>

nc -vnzu  5x.253.51.xxx 4501
Connection to 5x.253.51.xxx 4501 port [udp/*] succeeded!
-u Use UDP
-v verbose
-z  specifies that nc should just scan for listening daemons, without sending any data to them

nc -zv google.com 80
Connection to google.com 80 port [tcp/http] succeeded!

nc -zv google.com 443
Connection to google.com 443 port [tcp/https] succeeded!

Related commands

• iperf
• pv </dev/zero | ssh REMOTE_SERVER 'cat >/dev/null'
• nping

See also

• OpenSSH (changelog): /etc/ssh/sshd_config | /etc/ssh/ssh_config | ~/.ssh/ | openSSL | sshd logs | sftp | scp | authorized_keys | ssh-keygen | ssh-keyscan | ssh-add | ssh-agent | ssh | Ssh -O stop | ssh-copy-id | CheckHostIP | UseKeychain, OpenSSF
• telnet, netcat, nc, nc -l, ncat, socat, ngrok
• Security tools: Vulnerability scanner, port scan, Host sweep, nmap, nping, ncat, nc, psad, Gordon Lyon
• Security: Security portfolio, Security standards, Hardening, CVE, CWE, Wireless Network Hacking, vulnerability scanner, Security risk assessment, SCA, Application Security Testing, OWASP, Data leak, NIST, SANS, MITRE, Security policy, Access Control attacks, password policy, password cracking, Password manager, MFA, OTP, UTF, Firewall, DoS, Software bugs, MITM, Certified Ethical Hacker (CEH) Contents, Security+ Malware, FIPS, DLP, Network Access Control (NAC), VAPT, SIEM, EDR, SOC, pentest, PTaaS, Clickjacking, MobSF, Janus vulnerability, Back Orifice, Backdoor, CSO, CSPM, PoLP, forensic, encryption, Keylogger, Pwn2Own