Hi All,
I wonder if anyone can help me clarify the following, we start receiving standard ATP alerts for the past month as per bellow, usually im able to investigate this alerts and they either are DNS recursive queries performed by out forwarders on Spam domain emails received and rejected by the SMTP proxy, or Web sessions hijack attempts trying to redirect traffic to malicious domains, but recently i been baffled by a a recurrent alert as bellow where im not able to make much sense, i parsed the logs for our SMTP proxy that shows traffic to a Tor node from what i can only assume being SMTP connections rejected by the UTM does anyone have any idea on this ?
A threat has been detected in your network The source IP/host listed below was found to communicate with a potentially malicious site outside your company.
Advanced Threat ProtectionDetails Total Events: 2 User/Host Threat Name Destination Events Origin 1 192.168.7.250 C2/Generic-A 185.220.100.254 2 192.168.7.250 C2/Generic-A 185.220.100.254
Hi Balfson
The ATP reports the standard, a threat has been detected as per bellow
A threat has been detected in your networkThe source IP/host listed below was found to communicate with a potentially malicious site outside your company.
Details about the alert:
Threat name....: C2/Generic-ADetails........: www.sophos.com/.../C2~Generic-A.aspxTime...........: 2021-10-27 12:50Traffic blocked: yes
The traffic then points to our DNS forwarder: ( AFCd UDP C2/Generic-A 192.168.7.250 →1.1.1.1) after parsing the logs from our internal DNS server i can see the requests from our UTM to the Exit node going through our external DNS forwarders, but no idea to what is causing the UTM to contact the Node, my idea initially was based on a DNS query on an Spam email received by the SMTP proxy but not entirely sure...
07FC PACKET 000000B9471601E0 UDP Rcv 192.168.7.254 c213 Q [0001 D NOERROR] A (10)tor-exit-3(4)zbau(7)f3netze(2)de(0)
07FC PACKET 000000B946134120 UDP Snd 1.1.1.1 0735 Q [0001 D NOERROR] A (10)tor-exit-3(4)zbau(7)f3netze(2)de(0)
0678 PACKET 000000B946134120 UDP Snd 1.0.0.1 0735 Q [0001 D NOERROR] A (10)tor-exit-3(4)zbau(7)f3netze(2)de(0)
May we see the relevant log lines from the ATP log?
Cheers - Bob
Balfson,
This are the most up to date logs of a fresh incident, as per the SMTP proxy the utm is rejecting a connection from a tor node, that im trying to decipher why the constant attempt connections, as we have no internal hosts using mail servers
SMTP PROXY2021:11:07-06:43:35 srvutm-1 exim-in[6731]: 2021-11-07 06:43:35 SMTP connection from [185.220.100.243]:4524 (TCP/IP connection count = 2)2021:11:07-06:43:50 srvutm-1 exim-in[4881]: 2021-11-07 06:43:50 SMTP connection from tor-exit-16.zbau.f3netze.de [185.220.100.243]:4524 lost D=14s
ATP192.168.200.104 C2/Generic-A 185.220.100.243 192.168.7.250 C2/Generic-A 185.220.100.243 192.168.200.103 C2/Generic-A 185.220.100.243 192.168.200.113 C2/Generic-A 185.220.100.243 192.168.200.104 C2/Generic-A 185.220.100.243 192.168.7.250 C2/Generic-A 185.220.100.243 192.168.200.103 C2/Generic-A 185.220.100.243 192.168.200.113 C2/Generic-A 185.220.100.243
ATP LIVE LOG
06:43:40 AFCd UDP C2/Generic-A 192.168.200.103 → 1.0.0.1 drop 06:43:40 AFCd UDP C2/Generic-A 192.168.200.113 → 1.1.1.1 drop 06:43:42 AFCd UDP C2/Generic-A 192.168.7.250 → 1.0.0.1 drop 06:43:43 AFCd UDP C2/Generic-A 192.168.200.104 → 1.0.0.1 drop 06:43:47 AFCd UDP C2/Generic-A 192.168.200.103 → 1.1.1.1 drop 06:43:48 AFCd UDP C2/Generic-A 192.168.7.250 → 1.1.1.1 drop 06:43:49 AFCd UDP C2/Generic-A 192.168.200.104 → 1.1.1.1 drop 06:43:51 AFCd UDP C2/Generic-A 192.168.200.103 → 1.0.0.1 drop 06:43:52 AFCd UDP C2/Generic-A 192.168.7.250 → 1.0.0.1 drop 06:43:52 AFCd UDP C2/Generic-A 192.168.200.104 → 1.0.0.1 drop