Ci sono diverse voci nel file di registro del mio router che mostrano recenti tentativi DoS su alcune delle sue porte. Sembrano così:
[DoS Attack: ACK Scan] from source: 213.61.245.234, port 80, Friday, November 21,2014 11:37:59
[DoS Attack: ACK Scan] from source: 80.239.159.8, port 443, Friday, November 21,2014 11:18:09
...
[DoS Attack: RST Scan] from source: 195.39.197.142, port 30732, Wednesday, November 19,2014 22:12:35
[DoS Attack: ACK Scan] from source: 31.13.91.117, port 443, Wednesday, November 19,2014 17:56:38
[DoS Attack: ACK Scan] from source: 88.221.82.74, port 443, Wednesday, November 19,2014 17:56:33
[DoS Attack: ACK Scan] from source: 31.13.91.117, port 443, Wednesday, November 19,2014 17:56:06
[DoS Attack: ACK Scan] from source: 88.221.82.74, port 443, Wednesday, November 19,2014 17:56:01
[DoS Attack: ACK Scan] from source: 31.13.91.117, port 443, Wednesday, November 19,2014 17:55:50
[DoS Attack: ACK Scan] from source: 88.221.82.74, port 443, Wednesday, November 19,2014 17:55:44
[DoS Attack: ACK Scan] from source: 31.13.91.117, port 443, Wednesday, November 19,2014 17:55:38
[DoS Attack: ACK Scan] from source: 88.221.82.74, port 443, Wednesday, November 19,2014 17:55:36
[DoS Attack: ACK Scan] from source: 31.13.91.117, port 443, Wednesday, November 19,2014 17:55:36
[DoS Attack: ACK Scan] from source: 88.221.82.74, port 443, Wednesday, November 19,2014 17:55:30
[DoS Attack: RST Scan] from source: 128.199.49.106, port 18668, Wednesday, November 19,2014 15:06:46
Ho provato la scansione dell'IP pubblico del mio router per le porte aperte:
sudo nmap <my-public-ip> -Pn --reason --top-ports 10
Starting Nmap 6.47 ( http://nmap.org ) at 2014-11-21 16:02 CET
Nmap scan report for <public-hostname> (<my-public-ip>)
Host is up, received user-set.
PORT STATE SERVICE REASON
21/tcp filtered ftp no-response
22/tcp filtered ssh no-response
23/tcp filtered telnet no-response
25/tcp filtered smtp no-response
80/tcp filtered http no-response
110/tcp filtered pop3 no-response
139/tcp filtered netbios-ssn no-response
443/tcp filtered https no-response
445/tcp filtered microsoft-ds no-response
3389/tcp filtered ms-wbt-server no-response
Sono curioso, come fa il mio router a sapere che ognuno di questi è un attacco DoS in primo luogo? Questi casi di utilizzo di nmap
sono aggressivi in qualche modo? E dovrei essere preoccupato per questi attacchi?