Solved

Help we are sending spam from somewhere inside our domain!

Posted on 2006-10-26
14
173 Views
Last Modified: 2013-12-04
Hello Experts!
Earlier today, I found out we had been listed by SPAMCOP (http://spamcop.net/bl.shtml) as an originator of spam email, and also with PSBL (http://psbl.surriel.com). Can anyone please point me in the right direction as far as finding out a way to see if any of the PCs inside our domain are infected with some kind of spamware?

Thanks a lot!
0
Comment
Question by:RAMCIT
  • 7
  • 4
  • 3
14 Comments
 
LVL 16

Accepted Solution

by:
AdamRobinson earned 500 total points
ID: 17812895
Assuming you are running in a 2000/2003 environment, see this link:

http://www.petri.co.il/preventing_exchange_2000_2003_from_relaying.htm

You can find many other solutions easily by Googling for how to close an Open Mail Relay in your Domain Operating System Environment

0
 

Author Comment

by:RAMCIT
ID: 17812920
Actually Im runing Exchange 5.5 on an NT enviromnent.
0
 
LVL 16

Expert Comment

by:AdamRobinson
ID: 17812969
0
Ransomware-A Revenue Bonanza for Service Providers

Ransomware – malware that gets on your customers’ computers, encrypts their data, and extorts a hefty ransom for the decryption keys – is a surging new threat.  The purpose of this eBook is to educate the reader about ransomware attacks.

 

Author Comment

by:RAMCIT
ID: 17813886
ll, according to http://www.dnsreport.com/ we reject releys.
0
 
LVL 16

Expert Comment

by:AdamRobinson
ID: 17813970
If you open the queues in your Exchange System Manager, do you see a lot of mails waiting to be sent?
0
 

Author Comment

by:RAMCIT
ID: 17814010
more than usual yes
0
 
LVL 16

Expert Comment

by:AdamRobinson
ID: 17814027
Ok, I know DNS Report shows you reject relays, but try following the instructions in the link above and see if they go away. ;)
0
 

Author Comment

by:RAMCIT
ID: 17814048
Well I cannot seem to get into the server via telnet, says:

Server allows NTLM authentication only
0
 
LVL 16

Expert Comment

by:legalsrl
ID: 17828211
OK....

What AV and AntiSpyware do you use ?

Also, if you are using cisco routers let me know as I've got some neat tricks for these.

Cheers
Si


0
 

Author Comment

by:RAMCIT
ID: 17834456
Well on this server we have Trend Micro Scanmail for the exchange
No active antispyware.
0
 

Author Comment

by:RAMCIT
ID: 17834460
oh and this T1 connection uses a Cisco 2600 router with a watchguard firebox firewall.
0
 
LVL 16

Expert Comment

by:legalsrl
ID: 17836570
Does your Cisco router have Netflow enabled ?

Thanks
Si
0
 

Author Comment

by:RAMCIT
ID: 17836586
I have no idea
0
 
LVL 16

Expert Comment

by:legalsrl
ID: 17837366
OK,

OK, from a quick google, the 2600 routers do have Netflow on them.

Try this

Go here ---> http://www.manageengine.co.uk/

Download NetFlow Analyzer and install it....configure the router as per the instructions in the documentation to enable netflow packets and then leave it to run for an hour.

Go back in to NetFlow Analyzer and you will see a list of traffic broken down by type and then you see which machines are sending large amounts of SMTP traffic.

Let me know if you get stuck

Thanks
Si
0

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Recently, a new law in my state forced us to get a top-to-bottom analysis of all of our contract client's networks. While we have documentation, it was spotty at best for some - and in any event it needed to be checked against reality. That was m…
OfficeMate Freezes on login or does not load after login credentials are input.
This video shows how to use Hyena, from SystemTools Software, to bulk import 100 user accounts from an external text file. View in 1080p for best video quality.
A short tutorial showing how to set up an email signature in Outlook on the Web (previously known as OWA). For free email signatures designs, visit https://www.mail-signatures.com/articles/signature-templates/?sts=6651 If you want to manage em…

828 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question