2

We have a zimbra email server and one of the email accounts was compromised. The problem we have now is that a lot of spams are sent from that server and we cannot identify which account is compromised.

In the mailq we can only see the from email, but this is a fake email address.

Is there a way to identify the real auth user who is sending those emails?

  • iptraf can help you guess which ip adresses does a lot of traffic with the compromised server. tcpdump may also be a good tool. – bgtvfr Apr 25 '18 at 8:19
  • Thank you @bgtvfr, but this is not a solution. We have 3000 accounts, some of them are really sending a lot of emails, not sure the traffic analyze will make sense. – Milos Apr 25 '18 at 8:40
1

You can either grep logs for senders like

grep sasl_username /var/log/maillog

or use this script to show aggregate statistics

#!/usr/bin/python2
from __future__ import print_function

import re
re_sasl = re.compile(r'sasl_username=(.*)\s*')

senders = {}

for line in open('/var/log/maillog'):
    m = re_sasl.search(line.strip())
    if m:
        username = m.group(1)
        if username in senders:
            senders[username] += 1
        else:
            senders[username] = 1

print("Top senders:")
for username, count in sorted(senders.iteritems(), key=lambda x: x[1], reverse=True):
    print("\t{0:5d} {1}".format(count, username))
0

Please use this command to get compromise account details

cat zimbra.log | sed -n 's/.*sasl_username=//p' | sort | uniq -c | sort -n 

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.