I woke up this morning and could see over 1000+ of these alerts.

They came in the time space 23:34 - 23:35.
Can anybody tell me what that was about and should I be worried for an eventual DDoS attack?

I am running pfsense and behind that box I have my LAN and a NIC where my server is in a separate environment.

Snort Alter

  • There isn't a lot for us to go on - the source port is 5060, which is SIP/VOIP, and it's coming from Portugal. Is there anything else you can tell us? – schroeder Mar 26 '15 at 21:22
  • In general, 1000 bad connections in a minute, which then stop, isn't that big of a deal. Without any further data, I might say that someone misconfigured their VOIP server for a moment. – schroeder Mar 26 '15 at 21:27
  • I have tried to identify the source and he is hiding behind a proxy. That is actually the only thing I know for sure. My firewall and system logs doesn't show any signs of brute force or any "bad Behavior" activity. – Daniel Guldberg Aaes Mar 26 '15 at 21:32
  • Most likely it was already blocked by the firewall before it even reached snort, so I don't think it's anything to worry about. If it were a DDos attempt, it would last a lot longer than 1 minute. Snort in general generates tons of alerts, most of which are safe to ignore. – tlng05 Mar 27 '15 at 1:56

This is probably a bad configured scanning(attempting) of the communications compagny in Portugal. Since the ip-range might be the same as yours. Or they misconfigured some other connection ip's.

Nevertheless i don't think this commucation compagny is trying to hack you. Unless you have valuable information ;).



More info:

inetnum: -
netname:        NOS
descr:          NOS COMUNICACOES S.A.
country:        PT
admin-c:        NVSA1-RIPE
tech-c:         NVST1-RIPE
status:         ASSIGNED PA
mnt-by:         IP-MNT
source:         RIPE # Filtered

Wikipedia Source Nos communications:


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