Exchange 2013 Spam in Queue for Citibank

Hi,
I'm having an issue with Microsoft Exchange and spam being sent from that server.  I'm seeing tons of messages from alerts@citiybank.com going out to unsuspecting users across the web.  Some of them have mx-b.mail.citi.com in the header.

Now I wasn't the one who setup this so I'm not sure how to find logs or whatever else you all might need to help isolate the issue.  I've changed all of the passwords on my Domain and it's users and have tried to isolate one of the IP addresses I saw within the messages.   That part has not worked.

Right now I'm being blocked from sending legitimate emails to gmail and yahoo.
jtoney7852Asked:
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Simon Butler (Sembee)ConsultantCommented:
Due to the way Exchange works, the emails could still be processing.
Did you restart the transport service after changing the passwords? If so, that has probably stopped new emails.
You will need to empty the queues out to begin with, only then look at dealing with the IP address reputation.

IP address isolation is a waste of time, just get the queues cleared first.

Simon.

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jtoney7852Author Commented:
Let me restart that service now.  I'm sure the machine was restarted recently.
jtoney7852Author Commented:
I've restarted the service but I still see a huge amount of spam messages going through.  

Identity: Exchange\261934\64896955844974
Subject: Suspicious Account Activity Reference q3SIzzS
Internet Message ID: <71d5a526a9324f96a1b483cd5f8d3a16@citibank.com>
From Address: alerts-26fAzXY@citibank.com
Status: Ready
Size (KB): 40
Message Source Name: SMTP:Client Proxy
Source IP: 195.62.16.36
SCL: 0
Date Received: 3/17/2015 6:34:16 AM
Expiration Time: 3/19/2015 6:34:16 AM
Last Error:
Queue ID: Exchange\261934
Recipients:  *****@aol.com;2;2;[{LRT=};{LED=};{FQDN=};{IP=}];0;CN=SendConnector,CN=Connections,CN=Exchange Routing Group (DWBGZMFD01QNBJR),CN=Routing Groups,CN=Exchange Administrative Group (FYDIBOHF23SPDLT),CN=Administrative Groups,CN=First Organization,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=DOMAIN,DC=LOCAL
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jtoney7852Author Commented:
I've blocked traffic from 195.62.16.36 for now but I'm not sure if that will fix this issue.
jtoney7852Author Commented:
I'm also seeing this:

Identity: Exchange\261911\64905545779429
Subject: Undeliverable: Suspicious Account Activity Reference h7dAoVu
Internet Message ID: <b53c0dac-aad7-4018-9f56-9146cbb5fb43@Exchange.DOMAIN.LOCAL>
From Address: <>
Status: Ready
Size (KB): 40
Message Source Name: DSN
Source IP: 255.255.255.255
SCL: -1
Date Received: 3/17/2015 8:55:46 AM
Expiration Time: 3/19/2015 8:55:46 AM
Last Error:
Queue ID: Exchange\261911
Recipients:  alerts-KTN6R0z@citibank.com;2;2;[{LRT=};{LED=};{FQDN=};{IP=}];0;CN=SendConnector,CN=Connections,CN=Exchange Routing Group (DWBGZMFD01QNBJR),CN=Routing Groups,CN=Exchange Administrative Group (FYDIBOHF23SPDLT),CN=Administrative Groups,CN=First Organization,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=DOMAIN,DC=LOCAL
Simon Butler (Sembee)ConsultantCommented:
Restarting the service will not clear the problem.
All it will do is stop new messages from being delivered to the server.
Furthermore the post you have put above is an NDR. Do you have recipient filtering enabled on the server? If not then you should enable it, as it will stop the server being abused with NDR spam.

When you have had something like this happen, the first thing you have to do is stop new emails. You can now look at clearing the queues of those messages.

Simon.
jtoney7852Author Commented:
I've cleared the queue numerous times.  And I don't know how to enable recipient filtering.
Simon Butler (Sembee)ConsultantCommented:
Due to the way that Exchange processes emails, it can take a number of attempts to completely clear the queues.
When a spammer manages to compromise a server they will dump 1000s of messages on the server. Remember you are seeing just the failed messages, many more will have been delivered.

Recipient filtering is part of the anti spam agents.

This is the TechNet guide on installing the agents:
https://technet.microsoft.com/en-us/library/bb201691(v=exchg.150).aspx

Then enable it thus:
Set-RecipientFilterConfig -Enabled $true

Restart Transport again once you have done so.

Simon.
jtoney7852Author Commented:
Where could I see the messages that are going out?  A log?  If so where do I enable and see that?
jtoney7852Author Commented:
Also, for the Set-Recipient command....

WARNING: The command completed successfully but no settings of 'RecipientFilterConfig' have been modified.
Simon Butler (Sembee)ConsultantCommented:
That would suggest that you already had the setting enabled.
You may want to do a telnet test to confirm that an email to an unknown recipient is being rejected.

Messages going out are not logged by default, other than what you can get on Message Tracking. You can enable logging on the connectors, but they will generate large amounts of logs if you aren't careful.

Simon.
jtoney7852Author Commented:
Ok I need to know how to enable this, at least for a few minutes.  Remember, I'm not very familiar with how Exchange works so please give as detailed information as possible.  Thank you
Simon Butler (Sembee)ConsultantCommented:
Logging is enabled on the properties of the Send and Receive connectors within ECP.
After enabling it you need to restart Exchange Transport service for the change to take effect.
The location of the logs is set on the properties of the server in ECP, under Transport Logs.

Simon.
Mohammad Mahboob RahmatiSr . IT System Administration EngineerCommented:
please check the properties of the receive connectors: Default Exchange server and Default Frontend Server, on Security, check if Anonymous is checked, and if yes, uncheck it. After that you have to restart the Microsoft Exchange transport and the Microsoft Exchange Frontend Transport services to apply it.
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