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The source appears to be your own computer: 192.168.1.120. It's traffic that's going out to a web server, which you can tell by the DPT of 80. The high source port is to be expected.
The source appears to be your own computer: 192.168.1.120. It's traffic that's going out to a web server, which you can tell by the DPT of 80. The high source port is to be expected.
Hi Olroy, thanks for replying!
The source is my own computer. If I type the remote IP numbers in my web browser, I never get a web page. So it is not a web server, who gives "normal" info. Also I never saw this behavior until a few weeks ago.
So I am worried about this traffic. And I want to investigate further.
What should I do to get more information about this trafic?
I just picked 68.67.185.209 randomly and it seems to of had a history of being malicious at some point. I tried another and it seemed to be related to advertisements, which you would expect by surfing the web and such. Maybe you're just surfing the web and some content like banners are causing you to download content from somewhere else. What are you doing when you one of those outbound packets are dropped?
I'm not sure how many IPs are malicious or what they are doing from the little I've seen so far. You can use tcpdump to capture traffic for a while and then go back and investigate the contents with tcpdump or an updated version of Wireshark.
Code:
sudo tcpdump -i <interface> -s0 -nn -w tcp80.pcap 'tcp port 80 or udp port 53'
Obviously, if you're using a blacklist of some kind for your IP tables rules, that would explain a lot. Do you know why the traffic is being dropped in the first place?
I just picked 68.67.185.209 randomly and it seems to of had a history of being malicious at some point. I tried another and it seemed to be related to advertisements, which you would expect by surfing the web and such. Maybe you're just surfing the web and some content like banners are causing you to download content from somewhere else. What are you doing when you one of those outbound packets are dropped?
I'm not sure how many IPs are malicious or what they are doing from the little I've seen so far. You can use tcpdump to capture traffic for a while and then go back and investigate the contents with tcpdump or an updated version of Wireshark.
Code:
sudo tcpdump -i <interface> -s0 -nn -w tcp80.pcap 'tcp port 80 or udp port 53'
Obviously, if you're using a blacklist of some kind for your IP tables rules, that would explain a lot. Do you know why the traffic is being dropped in the first place?
Perhaps I am surfing at that time. It is my desktop computer... But I did not relate the two together.
I have a list of "bad" ip's (who accesses my server in the past with strange stuff). But these are dropped before it reaches the "LOG" file.
In my IpTables.sh, I have:
Code:
$IPT -A OUTPUT -p tcp --dport 80 -m state --state NEW -j ACCEPT
So only new trafic is allowed to pass. My conclusion: it is related.
The next time, when I am at my desktop, I start the tail -f on my logfile and the tcpdump first. Than see what happens.
No problem. Someone correct me if I'm wrong, but if that's the only output rule you have, you might need to change the rule to:
Code:
$IPT -A OUTPUT -p tcp --dport 80 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
However, if that's your only rule in OUTPUT, I would think you'd have to have a default accept OUTPUT policy because you'd need other protocols to send traffic out like DNS to get any use out of your computer's network connection.
No problem. Someone correct me if I'm wrong, but if that's the only output rule you have, you might need to change the rule to:
Code:
$IPT -A OUTPUT -p tcp --dport 80 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
However, if that's your only rule in OUTPUT, I would think you'd have to have a default accept OUTPUT policy because you'd need other protocols to send traffic out like DNS to get any use out of your computer's network connection.
he he he.... It is not the only rule.
I started my rules with a drop on each chain and a log rule. Than I added the ACCEPT rules as tight as possible, until the computer can do it's job.
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Do you know why the traffic is being dropped in the first place?
