← Port Encyclopedia
4000
ICQ
TCP
Messaging
Low Risk
ICQ instant messaging — legacy chat protocol
🔍 How to Scan Port 4000
nmap -sV -p 4000 target
nmap -sV -sC --script=banner -p 4000 target
nc -zv target 4000
🛡️ Security Considerations
- Scan port 4000 with
nmap -sVto identify the exact service and version - If ICQ is not needed, close or firewall this port immediately
- Check for default credentials if a management interface runs on this port
- Use
searchsploit icqto find known exploits - Monitor traffic on port 4000 with Wireshark or tcpdump for anomalies
- Ensure the service is patched to the latest version to prevent known CVE exploitation