From: "Scott" <
[email protected]>
| I have a client with about 25 workstations and one of them is sending out
| spam. How can I block all clients from sending anything out port 25? They
| have simple Linksys Router as the gateway and windows 2003 small business
| Server. Is there some free software I can install on the clients that will
| block outgoing SMTP (Port 25)?
I always suggest blocking both TCP and UDP ports 135 ~ 139 and 445 on any SOHO Router. You
can simply add TCP/UDP port 25 to that list.
However, that will block all outgoing email other than web page based (http) email services.
How this can be implemented will be based upon what this "client" does for email.
Anyway, This is a bamndage approach and doesn't cure the problem.
What is this spam ?
Is is deliberate ?
Is is an infected PC with a spamBOT ?
If it is deliberate, the employee should be warned once and if the action is repeated, the
employee should be fired.
A company Authorized Use Poliocy (AUP) should be created and *all employees* should read the
AUP and sign it.
If this is a spamBOT then all PCs should be scanned with ant virus utilities and and the PCs
should be re-examined for "proper" anti malware protection.
The following can be used to scan the client computers for spamBOTs and other malware...
Download MULTI_AV.EXE from the URL --
http://www.ik-cs.com/programs/virtools/Multi_AV.exe
To use this utility, perform the following...
Execute; Multi_AV.exe { Note: You must use the default folder C:\AV-CLS }
Choose; Unzip
Choose; Close
Execute; C:\AV-CLS\StartMenu.BAT
{ or Double-click on 'Start Menu' in C:\AV-CLS }
NOTE: You may have to disable your software FireWall or allow WGET.EXE to go through your
FireWall to allow it to download the needed AV vendor related files.
C:\AV-CLS\StartMenu.BAT -- { or Double-click on 'Start Menu' in C:\AV-CLS}
This will bring up the initial menu of choices and should be executed in Normal Mode.
This way all the components can be downloaded from each AV vendor's web site.
The choices are; Sophos, Trend, McAfee, Kaspersky, Exit this menu and Reboot the PC.
You can choose to go to each menu item and just download the needed files or you can
download the files and perform a scan in Normal Mode. Once you have downloaded the files
needed for each scanner you want to use, you should reboot the PC into Safe Mode [F8 key
during boot] and re-run the menu again and choose which scanner you want to run in Safe
Mode. It is suggested to run the scanners in both Safe Mode and Normal Mode.
When the menu is displayed hitting 'H' or 'h' will bring up a more comprehensive PDF help
file.
http://www.ik-cs.com/multi-av.htm
Additional Instructions:
http://pcdid.com/Multi_AV.htm
* * * Please report back your results * * *
