I have a dns server running bind without iptables configuration. Running some scanners with nmap, I found that no root in some high moments ports are open but soon close, and stay in that loop. When I walk with root these ports do not appear at any time.
Here is an output of nmap:
Host is up (0.00022s latency).
Scanned at 2016-09-10 01:04:48 UTC for 0s
Not shown: 64996 closed ports
PORT STATE SERVICE
22/tcp open ssh
53/tcp open domain
111/tcp open rpcbind
52347/tcp open unknown
And a moment later ...
Host is up (0.00022s latency).
Scanned at 2016-09-10 01:04:49 UTC for 1s
Not shown: 64994 closed ports
PORT STATE SERVICE
22/tcp open ssh
53/tcp open domain
111/tcp open rpcbind
38248/tcp open unknown
52347/tcp open unknown
55806/tcp open unknown
Output of netstat -ltnp
Conexões Internet Ativas (sem os servidores)
Proto Recv-Q Send-Q Endereço Local Endereço Remoto Estado PID/Program name
tcp 0 0 127.0.0.1:953 0.0.0.0:* OUÇA 7209/named
tcp 0 0 0.0.0.0:52347 0.0.0.0:* OUÇA 902/rpc.statd
tcp 0 0 0.0.0.0:111 0.0.0.0:* OUÇA 888/rpcbind
tcp 0 0 XXX.XX.XX.X:53 0.0.0.0:* OUÇA 7209/named
tcp 0 0 XXX.XXX.XX.X:53 0.0.0.0:* OUÇA 7209/named
tcp 0 0 127.0.0.1:53 0.0.0.0:* OUÇA 7209/named
tcp 0 0 0.0.0.0:22 0.0.0.0:* OUÇA 935/sshd
tcp 0 0 127.0.0.1:631 0.0.0.0:* OUÇA 1258/cupsd
tcp6 0 0 :::48323 :::* OUÇA 902/rpc.statd
tcp6 0 0 :::111 :::* OUÇA 888/rpcbind
tcp6 0 0 :::22 :::* OUÇA 935/sshd
tcp6 0 0 ::1:631 :::* OUÇA 1258/cupsd
My system is Linux lDebian13 3.16.0-4-amd64 #1 SMP Debian 3.16.36-1+deb8u1 (2016-09-03) x86_64 GNU/Linux
What is it these ports? will bug? is a backdoor? how can I get information from them?
