How to find spambot? Got network abuse report from my ISP
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@johnpoz said in How to find spambot? Got network abuse report from my ISP:
port 5353.
has zero to do with email - its mdns... No you shouldn't have those ports open to the internet.
I know it has nothing to do with email. I just wonder that my ISP is sending abuse mails to a lot of people about it and most of the time the PS4 was the problem.
I did install PRTG Network Monitor. Now i need to find out how that works.
Looks like flying a Boeing 747.I need to monitor the WAN port? I do that with softflowd?
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Ok there are 18 new events on that abuse site this morning 2:52am (Dec 14).
pfSense is running on a standalone machine (no HyperV) and all the mail ports are blocked.I have now PRTG running but I'm not sure with some settings.
Should i leave the "Source Address" default or should i set it to LAN since I'm only looking for mails going out?
For "Syslog Contents" i only selected "Firewall Events".
I did set the "Include Filter" in PRTG to "message[igb1]" because I'm only looking for what is blocked on the LAN interface.
This is what i have then:
I cant figure out how to filter that by port or how to make it more readable.
This two messages is PRTG trying to send some mails.Now that NetFlow thing. I have no idea what values to use on Max Flows, Hop Limit and on all this timeout settings.
Is it enough to select "IP" in "Flow Tracking Level"?
This this from PRTG but is over my head:
Make sure that you set an Active Flow Timeout in the sensor settings that is one minute greater than the flow timeout value that you set in the target device.
For more information, see https://kb.paessler.com/en/topic/66485.I did set the filter to Port[25] or Port[465] or Port[587] or Port[2525] or Port[2526]
Here i did retrieve and send a mail with Thunderbird. Is it normal that i don't see the IP from my workstation?
This is some other stuff i see. Stuff i don't know what it is:
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After my last posting i see this:
And ~50 new entries on the abuse website.
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Have you considered that you might be relaying spam from an external source, rather than originating the spam on your own network - running an open relay?
Show us a screenshot of your WAN rules.
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There is a whole bunch of traffic to 25 in that listing... But its showing your wan IP..
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@MrGlasspoole :
What type of network is this: a home network or a business?If home, then NAT is going to mask the local host that is spamming when looking at traffic on the WAN interface. To see that IP, you need to put your tools on the LAN interface and then examine all devices you see initiating connections to an Internet host on ports 25, 465 and 587. A spambot will need to make outbound connections to other mail servers using one of those three ports. The source port is immaterial as it will be an ephemeral port. What matters is the destination port (one of the big 3 mail server ports). Once you find that traffic entering the LAN interface, examine the source IP addresses to find the infection.
If you have a business network with multiple subnets hanging off the firewall, you will follow the same process but just do it for each configured interface.
You could have an infected PC or even an infected IoT device (Smart TV, Smart Home Hub, etc.).
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@johnpoz said in How to find spambot? Got network abuse report from my ISP:
There is a whole bunch of traffic to 25 in that listing... But its showing your wan IP..
I did set softflowd to the WAN because if i understand it right: If it would be something in my LAN i would see it in the System Log?
@bmeeks said in How to find spambot? Got network abuse report from my ISP:
@MrGlasspoole :
What type of network is this: a home network or a business?If home, then NAT is going to mask the local host that is spamming when looking at traffic on the WAN interface. To see that IP, you need to put your tools on the LAN interface and then examine all devices you see initiating connections to an Internet host on ports 25, 465 and 587.
You could have an infected PC or even an infected IoT device (Smart TV, Smart Home Hub, etc.).Its a home network and as you can see in this threat the mail ports are blocked on the LAN interface and nothing raises an alert in the log.
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But how you suppose to figure out what is sending it? You need to see both!
Also what are you rules on your floating?
Do you have more than 1 IP? Looks like your public IP is different or you have more than 1, see traffic to x.x.36.95, and then your also showing traffic to 25 from x.x.35.103..
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There is nothing in floating.
pfSense is showing me a 176.xxx.xxx.xxx address on WAN.
On that abuse site the last reports are 88.xxx.xxx.xxx.I enabled softflowd now also on the LAN.
Is it normal that there is no time on every single entry in that IPFIX thing?For testing i did open the port on LAN and did send a mail and it shows up and has the 176.... address:
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So what is using that 88.x.x.x IP? Seems like it must be on the firewall...
Check the pfSense routing table in Diag > Routes, do both IPs appear there?
Is the WAN configured as DHCP? Could it just be pulling a new IP from the ISP there?
Steve
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Sure WAN is DHCP since the ISP router is in bridge mode.
This is what routes is showing:
The last abuse entries. Always new entries:
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Well that aint your IP...
Neither of them are.. atleast not with pfsense - do you have other devices connected to this isp?
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Only the pfSense WAN is connected to the ISP router/modem.
And that network abuse report has my customer ID.
That 176.199.143.125 in that report is the old IP.
Now its 176.xxx.xxx.174 that i see on the WAN in pfSense.
Most of the time when you restart the modem you get a new one.Its driving me crazy
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And how are you sure its not reports from some other guy that had that IP before you got it? ;)
That is part of the problem of changing IPs all the time - you can be held responsible for the sins of the guy that had it before you..
But you did show a bunch of traffic to 25...
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But i can see that 88.xxx.xxx.103 that is on top on that report also in softflowd?
@johnpoz said in How to find spambot? Got network abuse report from my ISP:
But you did show a bunch of traffic to 25...
And that is what I (we) trying to figure out? Where does it come from?
It does not come from the LAN because the ports are blocked...
Only pfSense is connected to the modem...I don't get it
That IPFIX log is full of mail port entries.
100 every 15 minutes...
Are this entries blocked stuff from outside? -
Look in your state table... What doe you see for those connections to 25.
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Diagnostics > States?
There is nothing with port 25, 587 or the 88.xxx.xxx.xxx IP.
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Well are you seeing the connections - you stated that your seeing 100 connections every 15 minutes... Watch it for a while.. that 88.x address not going to be in use any more since your on a different IP now.
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@MrGlasspoole said in How to find spambot? Got network abuse report from my ISP:
The funny thing is that the day before someone from my ISP was here because bridge mode did not work and there box sometimes did crash/reboot.
He was the only one with other devices.
He told me the router did not receive the last firmware automatically and made a reset to factory defaults. After that the router did pull the newest firmware.I am really curious about his situation, and somehow I suspect his router especially under the above statement...the firmware could be corrupted at no fault of anyone. If nothing is coming from LAN, it must be the router...does the router has any known vulnerabilities?
