Suspicious Traffic?

johnpoz

@deanfourie pfsense itself should not be sshing to random IPs.. Or even 80..

What does pfsense show for its state table for those IPs.. If pfsense or a client generated traffic then it would be in the state table.

You sure that is just not traffic inbound from that source port as a SA? That is method of scanning..

Sniff on your wan for those IPs - lets see the pcap file.

deanfourie

@johnpoz Can I attach PCAP?

ssh.cap

johnpoz

@deanfourie sure you can..

BTW those IPs are owned by Alibaba.com - well known website..

Again did you look in your state table?

deanfourie

@johnpoz could it be getting the port mappings all messed up because im double natting?

will check state table now.

deanfourie

WAN	tcp	192.168.8.2:12812 (172.16.101.17:50569) -> 20.198.119.84:443	ESTABLISHED:ESTABLISHED	270 / 150	25 KiB / 34 KiB	
WAN	tcp	192.168.8.2:18400 (172.16.101.17:50585) -> 74.125.68.188:5228	ESTABLISHED:ESTABLISHED	163 / 166	7 KiB / 18 KiB	
WAN	tcp	192.168.8.2:46821 (172.16.101.7:40860) -> 34.120.177.193:443	ESTABLISHED:ESTABLISHED	19 / 18	2 KiB / 5 KiB	
WAN	tcp	192.168.8.2:2211 (172.16.101.7:52014) -> 185.199.108.133:443	ESTABLISHED:ESTABLISHED	11 / 11	1 KiB / 5 KiB	
WAN	tcp	192.168.8.2:47425 (172.16.101.15:49690) -> 76.223.31.44:443	ESTABLISHED:ESTABLISHED	40 / 42	2 KiB / 17 KiB	
WAN	tcp	192.168.8.2:20743 (172.16.101.15:49408) -> 20.198.119.143:443	ESTABLISHED:ESTABLISHED	49 / 33	6 KiB / 9 KiB	
WAN	tcp	192.168.8.2:7210 (172.16.101.15:49738) -> 185.159.80.151:8886	ESTABLISHED:ESTABLISHED	317 / 449	13 KiB / 18 KiB	
WAN	tcp	192.168.8.2:11825 (172.16.101.15:49775) -> 74.125.200.188:5228	ESTABLISHED:ESTABLISHED	102 / 102	5 KiB / 12 KiB	
WAN	tcp	192.168.8.2:50350 (172.16.101.15:1025) -> 162.159.130.234:443	ESTABLISHED:ESTABLISHED	2.854 K / 3.08 K	128 KiB / 685 KiB	
WAN	udp	192.168.8.2:5477 -> 173.234.106.107:1194	MULTIPLE:MULTIPLE	4.046 K / 4.045 K	333 KiB / 327 KiB	
WAN	icmp	192.168.8.2:53676 -> 1.1.1.1:53676	0:0	4.023 K / 4.022 K	114 KiB / 114 KiB	
WAN	tcp	192.168.8.2:39097 (172.16.101.15:1503) -> 208.123.73.199:443	ESTABLISHED:ESTABLISHED	1.788 K / 1.927 K	479 KiB / 429 KiB	
WAN	tcp	192.168.8.2:57584 (172.16.101.15:12915) -> 151.101.165.2:443	ESTABLISHED:ESTABLISHED	1.074 K / 1.735 K	168 KiB / 1.86 MiB	
WAN	tcp	192.168.8.2:29269 (172.16.101.15:12923) -> 54.235.148.246:443	ESTABLISHED:ESTABLISHED	59 / 58	4 KiB / 14 KiB	
WAN	tcp	192.168.8.2:43248 (172.16.101.7:52032) -> 185.199.108.133:443	ESTABLISHED:ESTABLISHED	14 / 13	1 KiB / 5 KiB	
WAN	tcp	192.168.8.2:29264 (172.16.101.7:40878) -> 34.120.177.193:443	ESTABLISHED:ESTABLISHED	20 / 18	2 KiB / 5 KiB	
WAN	tcp	192.168.8.2:63243 (172.16.101.17:50822) -> 35.82.210.186:443	ESTABLISHED:FIN_WAIT_2	11 / 14	1 KiB / 8 KiB	
WAN	tcp	192.168.8.2:42063 (172.16.101.15:1083) -> 151.101.194.137:443	FIN_WAIT_2:FIN_WAIT_2	257 / 449	41 KiB / 533 KiB	
WAN	tcp	192.168.8.2:21220 (172.16.101.15:1087) -> 199.232.214.133:443	FIN_WAIT_2:FIN_WAIT_2	2.131 K / 3.173 K	146 KiB / 3.03 MiB	
WAN	tcp	192.168.8.2:25604 (172.16.101.15:1091) -> 151.101.130.137:443	FIN_WAIT_2:FIN_WAIT_2	309 / 499	31 KiB / 418 KiB	
WAN	tcp	192.168.8.2:7591 (172.16.101.7:40880) -> 34.120.177.193:443	ESTABLISHED:CLOSING	19 / 29	2 KiB / 7 KiB	
WAN	tcp	192.168.8.2:24193 (172.16.101.7:38508) -> 185.199.110.133:443	ESTABLISHED:ESTABLISHED	12 / 12	1 KiB / 5 KiB	
WAN	tcp	192.168.8.2:41881 (172.16.101.15:1318) -> 142.250.71.78:443	ESTABLISHED:ESTABLISHED	33 / 40	10 KiB / 10 KiB	
WAN	tcp	192.168.8.2:55573 (172.16.101.15:1352) -> 3.24.51.182:21	ESTABLISHED:ESTABLISHED	50 / 51	4 KiB / 6 KiB	
WAN	tcp	192.168.8.2:25728 (172.16.101.15:1378) -> 162.159.135.232:443	FIN_WAIT_2:FIN_WAIT_2	14 / 13	1 KiB / 6 KiB	
WAN	tcp	192.168.8.2:8063 (172.16.101.15:1410) -> 44.226.92.23:443	TIME_WAIT:TIME_WAIT	12 / 12	2 KiB / 8 KiB	
WAN	udp	192.168.8.2:9834 (172.16.101.15:65210) -> 142.250.67.10:443	MULTIPLE:MULTIPLE	21 / 24	5 KiB / 7 KiB	
WAN	tcp	192.168.8.2:55434 (172.16.101.17:50851) -> 52.41.50.6:443	FIN_WAIT_2:FIN_WAIT_2	11 / 12	2 KiB / 6 KiB	
WAN	tcp	192.168.8.2:57382 (172.16.101.15:1418) -> 35.82.210.186:443	TIME_WAIT:TIME_WAIT	12 / 11	2 KiB / 6 KiB	
WAN	tcp	192.168.8.2:54394 (172.16.101.15:1419) -> 202.124.124.90:80	FIN_WAIT_2:FIN_WAIT_2	6 / 5	346 B / 391 B	
WAN	tcp	192.168.8.2:22280 (172.16.101.15:1420) -> 44.226.92.23:443	FIN_WAIT_2:FIN_WAIT_2	14 / 11	3 KiB / 6 KiB	
WAN	tcp	192.168.8.2:44695 (172.16.101.15:1421) -> 35.82.210.186:443	TIME_WAIT:TIME_WAIT	12 / 12	2 KiB / 8 KiB	
WAN	tcp	192.168.8.2:1247 (172.16.101.15:1422) -> 35.82.210.186:443	FIN_WAIT_2:FIN_WAIT_2	12 / 12	2 KiB / 6 KiB	
WAN	tcp	192.168.8.2:17221 (172.16.101.15:1423) -> 202.124.124.91:80	FIN_WAIT_2:FIN_WAIT_2	6 / 5	346 B / 391 B	
WAN	udp	192.168.8.2:19584 (172.16.101.15:53957) -> 142.250.204.4:443	MULTIPLE:MULTIPLE	175 / 396	26 KiB / 376 KiB	
WAN	tcp	192.168.8.2:47504 (172.16.101.17:50852) -> 44.226.92.23:443	FIN_WAIT_2:FIN_WAIT_2	11 / 12	2 KiB / 6 KiB	
WAN	tcp	192.168.8.2:48004 (172.16.101.15:1426) -> 202.124.124.91:80	FIN_WAIT_2:FIN_WAIT_2	4 / 5	266 B / 391 B	
WAN	udp	192.168.8.2:23977 (172.16.101.15:62766) -> 142.250.67.14:443	MULTIPLE:MULTIPLE	40 / 55	6 KiB / 44 KiB	
WAN	udp	192.168.8.2:29747 (172.16.101.15:52600) -> 172.217.24.42:443	MULTIPLE:MULTIPLE	12 / 11	4 KiB / 7 KiB	
WAN	tcp	192.168.8.2:12425 (172.16.101.15:1427) -> 172.217.24.42:443	FIN_WAIT_2:FIN_WAIT_2	10 / 10	1 KiB / 6 KiB	
WAN	udp	192.168.8.2:35646 (172.16.101.15:64854) -> 172.217.167.110:443	MULTIPLE:MULTIPLE	18 / 21	6 KiB / 6 KiB	
WAN	udp	192.168.8.2:17732 (172.16.101.15:52777) -> 142.251.12.100:443	MULTIPLE:MULTIPLE	8 / 7	2 KiB / 3 KiB	
WAN	udp	192.168.8.2:25021 (172.16.101.17:61533) -> 172.217.167.110:443	MULTIPLE:MULTIPLE	10 / 11	3 KiB / 5 KiB	
WAN	udp	192.168.8.2:42623 (172.16.101.15:64825) -> 142.250.71.74:443	MULTIPLE:MULTIPLE	9 / 9	3 KiB / 4 KiB	
WAN	udp	192.168.8.2:14418 (172.16.101.15:58123) -> 142.250.66.238:443	MULTIPLE:MULTIPLE	9 / 10	4 KiB / 5 KiB	
WAN	udp	192.168.8.2:45098 (172.16.101.15:62002) -> 151.101.165.229:443	MULTIPLE:MULTIPLE	7 / 5	2 KiB / 4 KiB	
WAN	tcp	192.168.8.2:18827 (172.16.101.15:1430) -> 68.67.73.20:443	TIME_WAIT:TIME_WAIT	9 / 10	1015 B / 6 KiB	
WAN	tcp	192.168.8.2:11080 (172.16.101.15:1431) -> 68.67.73.20:443	TIME_WAIT:TIME_WAIT	23 / 27	6 KiB / 27 KiB	
WAN	tcp	192.168.8.2:5459 (172.16.101.15:1432) -> 68.67.73.20:443	TIME_WAIT:TIME_WAIT	10 / 10	1 KiB / 6 KiB	
WAN	tcp	192.168.8.2:2903 -> 204.61.216.50:53	FIN_WAIT_2:FIN_WAIT_2	6 / 5	366 B / 2 KiB	
WAN	tcp	192.168.8.2:28352 (172.16.101.15:1437) -> 44.226.92.23:443	TIME_WAIT:TIME_WAIT	11 / 11	2 KiB / 6 KiB	
WAN	tcp	192.168.8.2:4299 (172.16.101.15:1438) -> 202.124.124.90:80	FIN_WAIT_2:FIN_WAIT_2	5 / 5	306 B / 391 B	
WAN	tcp	192.168.8.2:43484 (172.16.101.15:1439) -> 208.123.73.73:443	TIME_WAIT:TIME_WAIT	21 / 35	5 KiB / 40 KiB	
WAN	tcp	192.168.8.2:51773 (172.16.101.15:1440) -> 208.123.73.73:443	TIME_WAIT:TIME_WAIT	14 / 15	4 KiB / 12 KiB	
WAN	tcp	192.168.8.2:1628 (172.16.101.15:1441) -> 208.123.73.73:443	ESTABLISHED:ESTABLISHED	5 / 4	809 B / 511 B	
WAN	tcp	192.168.8.2:38092 (172.16.101.15:1442) -> 208.123.73.73:443	ESTABLISHED:ESTABLISHED	9 / 9	993 B / 7 KiB	
WAN	tcp	192.168.8.2:24666 (172.16.101.15:1443) -> 208.123.73.73:443	ESTABLISHED:ESTABLISHED	5 / 4	809 B / 511 B	
WAN	tcp	192.168.8.2:8877 (172.16.101.15:1444) -> 208.123.73.73:443	ESTABLISHED:ESTABLISHED	9 / 9	993 B / 7 KiB	
WAN	tcp	192.168.8.2:49217 (172.16.101.15:1445) -> 208.123.73.73:443	ESTABLISHED:ESTABLISHED	8 / 9	941 B / 7 KiB	
WAN	tcp	192.168.8.2:20808 (172.16.101.15:1446) -> 35.82.210.186:443	FIN_WAIT_2:FIN_WAIT_2	12 / 11	3 KiB / 6 KiB	
WAN	tcp	192.168.8.2:10716 -> 199.180.180.63:53	TIME_WAIT:TIME_WAIT	5 / 5	327 B / 2 KiB	
WAN	tcp	192.168.8.2:27420 (172.16.101.15:1447) -> 44.226.92.23:443	ESTABLISHED:ESTABLISHED	12 / 12	2 KiB / 8 KiB	
WAN	tcp	192.168.8.2:31279 (172.16.101.15:1448) -> 44.226.92.23:443	FIN_WAIT_2:FIN_WAIT_2	12 / 12	2 KiB / 6 KiB	
WAN	tcp	192.168.8.2:65211 (172.16.101.17:50853) -> 35.82.210.186:443	FIN_WAIT_2:FIN_WAIT_2	11 / 12	2 KiB / 6 KiB	
WAN	udp	192.168.8.2:60136 -> 150.171.16.34:53	MULTIPLE:SINGLE	1 / 1	73 B / 89 B	
WAN	udp	192.168.8.2:34690 -> 202.124.124.84:53	MULTIPLE:SINGLE	1 / 1	76 B / 108 B	
WAN	tcp	192.168.8.2:62217 (172.16.101.15:1449) -> 202.124.124.91:80	FIN_WAIT_2:FIN_WAIT_2	5 / 5	306 B / 391 B	
WAN	tcp	192.168.8.2:43879 (172.16.101.15:1450) -> 202.124.124.91:80	FIN_WAIT_2:FIN_WAIT_2	6 / 5	346 B / 391 B	
WAN	udp	192.168.8.2:23297 (172.16.101.15:50903) -> 142.250.204.4:443	MULTIPLE:MULTIPLE	5 / 5	3 KiB / 3 KiB	
WAN	udp	192.168.8.2:5215 (172.16.101.5:123) -> 103.242.68.69:123	MULTIPLE:SINGLE	1 / 1	76 B / 76 B	
WAN	udp	192.168.8.2:7924 (172.16.101.5:123) -> 162.159.200.1:123	MULTIPLE:SINGLE	1 / 1	76 B / 76 B	
WAN	udp	192.168.8.2:20410 (172.16.101.5:123) -> 163.47.220.60:123	MULTIPLE:SINGLE	1 / 1	76 B / 76 B	
WAN	tcp	192.168.8.2:19162 (172.16.101.15:1451) -> 52.41.50.6:443	ESTABLISHED:ESTABLISHED	11 / 11	2 KiB / 6 KiB	
WAN	tcp	192.168.8.2:48761 (172.16.101.17:50854) -> 44.226.92.23:443	ESTABLISHED:ESTABLISHED	10 / 11	2 KiB / 6 KiB

johnpoz

@deanfourie I don't see any states to that 8. address.

So pfsense didn't create, nor did a client create a connection to there.. Do a simple filter on your state table for the IPs in question.

If you do not see any states then pfsense did not create the connection, nor did a client behind pfsense.

And what you could be seeing could be SA scan, that is being interpreted wrong???

But if your concerned that pfsense, or something behind pfsense is creating connections to somewhere it shouldn't be - look in the state table.. If a connection attempt was made from or through pfsense then a state would exist. Even if the connection was not established.

Here - trying to ping one of those IPs.. Even though not getting an answer, you can see the state in the state table from pfsense

deanfourie

@johnpoz Ok great ill do this.

I hate working with upstream gateways and double natting, would much rather put the router in bridged mode and get WAN IP from DHCP and boom! Last time I did this I was on the naughty list with the ISP. They warned me

I will do more careful watching of the state table. My concern is actually with the 4G router still though,

If its doing some sort of dodgy proxying at the 4G router, I'm not going to be able to see that from pfSense WAN side as its before the WAN interface.

I mean at the end of the day, it is a Huawei router...

I cant even disable TR-069 on it, nor can I change the LAN subnet mask.

stephenw10

If you're concerned about it the only thing you can really do is tunnel all your traffic through it so the router never sees inside it. There is obviously overhead to doing that though.

Steve

deanfourie

@stephenw10 I originally was routing all traffic through a VPN, however I got so many more weird connections as a result.

One question I do have is, would doubling NATting effect the results of the flows in ntopng.

Like matching ports and applications etc?

Thanks

stephenw10

No I wouldn't expect it to. The source/destination ports/IPs that ntop can see are still the same.

deanfourie

@stephenw10 said in Suspicious Traffic?:

No I wouldn't expect it to. The source/destination ports/IPs that ntop can see are still the same.

Thank you

deanfourie

Maybe someone could take a look at this capture. Lots of SSH from 192.168.8.2 which is my pfSense firewall.

Also a lot of TCP retransmissions. I'm not sure how my pfSense could be sending out SSH traffic?

capture.pcap

johnpoz

@deanfourie pfsense out of the box would not be doing any ssh outbound..

You would see retrans when you send a syn and you don't get an answer..

Did you look in your state table for those IPs to what behind pfsense might be trying to talk to those IPs.. Looks like Ips on your ISP network.

;; ANSWER SECTION:
22.239.24.86.in-addr.arpa. 86400 IN     PTR     cpc152131-stkp13-2-0-cust21.10-2.cable.virginm.net.

Dude do you have Ntopng running in discovery mode on your wan?? That would for sure freaking do it..

deanfourie

@johnpoz Heres what I found in the states table.

johnpoz

@deanfourie Dude stop having ntop try to discovery your wan.

deanfourie

@johnpoz oh that's not ntop that's the states table.

johnpoz

@deanfourie Again the only thing that would do what your seeing is ntop in discovery mode.. Turn it off and that traffic will stop..

Its not suspicious traffic - its ntop in discovery mode..

Why you would have it trying to discover your wan what is causing that traffic.

deanfourie

@johnpoz so you're telling me that ntop is creating these outbound ssh connections?

johnpoz

@deanfourie Yes - its discovery mode.. Is looking for stuff.. ssh (port 22) being one of the things it looks for.

Here is a recent thread - same sort of thing

https://forum.netgate.com/topic/172680/ntopng-sshguard

Here is the code from the ntop

https://github.com/ntop/ntopng/blob/dev/scripts/lua/modules/discover_utils.lua#L495

deanfourie

@johnpoz but would it not see this traffic only if this traffic existed? Hence why it's seeing it

I don't know what am I missing?