Backtracking EMAIL Messages

Tracking email back to its source:

Ask most people how they determine who sent them an email message and the response is almost universally, "By the From line." Unfortunately this symptomatic of the current confusion among internet users as to where particular messages come from and who is spreading spam and viruses. The "From" header is little more than a courtesy to the person receiving the message. People spreading spam and viruses are rarely courteous. In short, if there is any question about where a particular email message came from the safe bet is to assume the "From" header is forged.

So how do you determine where a message actually came from? You have to understand how email messages are put together in order to backtrack an email message. SMTP is a text based protocol for transferring messages across the internet. A series of headers are placed in front of the data portion of the message. By examining the headers you can usually backtrack a message to the source network, sometimes the source host. A more detailed essay on reading email headers can be found .

If you are using Outlook or Outlook Express you can view the headers by right clicking on the message and selecting properties or options.

Below are listed the headers of an actual spam message I received. I've changed my email address and the name of my server for obvious reasons. I've also double spaced the headers to make them more readable.


Return-Path:

X-Original-To: davar@example.com

Delivered-To: davar@example.com

Received: from 12-218-172-108.client.mchsi.com (12-218-172-108.client.mchsi.com [12.218.172.108])
by mailhost.example.com (Postfix) with SMTP id 1F9B8511C7
for ; Sun, 16 Nov 2003 09:50:37 -0800 (PST)

Received: from (HELO 0udjou) [193.12.169.0] by 12-218-172-108.client.mchsi.com with ESMTP id <536806-74276>; Sun, 16 Nov 2003 19:42:31 +0200

Message-ID:

From: "Maricela Paulson"

Reply-To: "Maricela Paulson"

To: davar@example.com

Subject: STOP-PAYING For Your PAY-PER-VIEW, Movie Channels, Mature Channels...isha

Date: Sun, 16 Nov 2003 19:42:31 +0200

X-Mailer: Internet Mail Service (5.5.2650.21)

X-Priority: 3

MIME-Version: 1.0

Content-Type: multipart/alternative; boundary="MIMEStream=_0+211404_90873633350646_4032088448"


According to the From header this message is from Maricela Paulson at s359dyxxt@yahoo.com. I could just fire off a message to abuse@yahoo.com, but that would be waste of time. This message didn't come from yahoo's email service.

The header most likely to be useful in determining the actual source of an email message is the Received header. According to the top-most Received header this message was received from the host 12-218-172-108.client.mchsi.com with the ip address of 21.218.172.108 by my server mailhost.example.com. An important item to consider is at what point in the chain does the email system become untrusted? I consider anything beyond my own email server to be an unreliable source of information. Because this header was generated by my email server it is reasonable for me to accept it at face value.

The next Received header (which is chronologically the first) shows the remote email server accepting the message from the host 0udjou with the ip 193.12.169.0. Those of you who know anything about IP will realize that that is not a valid host IP address. In addition, any hostname that ends in client.mchsi.com is unlikely to be an authorized email server. This has every sign of being a cracked client system.


Here's is where we start digging. By default Windows is somewhat lacking in network diagnostic tools; however, you can use the tools at to do your own checking.

davar@nqh9k:[/home/davar] $whois 12.218.172.108

AT&T WorldNet Services ATT (NET-12-0-0-0-1)
12.0.0.0 - 12.255.255.255
Mediacom Communications Corp MEDIACOMCC-12-218-168-0-FLANDREAU-MN (NET-12-218-168-0-1)
12.218.168.0 - 12.218.175.255

# ARIN WHOIS database, last updated 2003-12-31 19:15
# Enter ? for additional hints on searching ARIN's WHOIS database.

I can also verify the hostname of the remote server by using nslookup, although in this particular instance, my email server has already provided both the IP address and the hostname.

davar@nqh9k:[/home/davar] $nslookup 12.218.172.108

Server: localhost
Address: 127.0.0.1

Name: 12-218-172-108.client.mchsi.com
Address: 12.218.172.108

Ok, whois shows that Mediacom Communications owns that netblock and nslookup confirms the address to hostname mapping of the remote server,12-218-172-108.client.mchsi.com. If I preface a www in front of the domain name portion and plug that into my web browser, http://www.mchsi.com, I get Mediacom's web site.

There are few things more embarrassing to me than firing off an angry message to someone who is supposedly responsible for a problem, and being wrong. By double checking who owns the remote host's IP address using two different tools (whois and nslookup) I minimize the chance of making myself look like an idiot.

A quick glance at the web site and it appears they are an ISP. Now if I copy the entire message including the headers into a new email message and send it to abuse@mchsi.com with a short message explaining the situation, they may do something about it.

But what about Maricela Paulson? There really is no way to determine who sent a message, the best you can hope for is to find out what host sent it. Even in the case of a PGP signed messages there is no guarantee that one particular person actually pressed the send button. Obviously determining who the actual sender of an email message is much more involved than reading the From header. Hopefully this example may be of some use to other forum regulars.

Registry Hacking on Windows XP

Display legal notice on startup:

Wanna tell your friends about the do's and dont's in your computer when they login in your absence. Well you can do it pretty easily by displaying a legal notice at system start up.
REGEDIT
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system]
"legalnoticecaption"="enter your notice caption"
"legalnoticetext"="enter your legal notice text"

Automatic Administrator Login:

Well here's the trick which you can use to prove that Windows XP is not at all secure as multi-user operating system. Hacking the system registry from any account having access to system registry puts you in to the administrator account.
REGEDIT 4
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon]
"AutoAdminLogon"="1"

No Shutdown:

Wanna play with your friends by removing the shutdown option from start menu in their computer.
Just hack it down !!!
Regedit
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer
"NoClose"="DWORD:1"

Menu Delays:

Another minor and easy tweak to remove any delay from menus sliding out. For this you will need to use regedit (open regedit by going to Start -> Run..., then typing 'regedit' and pressing enter). The key you need to change is located in HKEY_CURRENT_USERControl PanelDesktop. The actual key is called MenuShowDelay - all you have to do is change the value to 0. Remember, you will have to re-boot your computer for this tweak to take effect.

GPEDIT.MSC And Autoplay

A great tweaking file that comes with XP is gpedit.msc. Go to Start -> Run... and then type in 'gpedit.msc' and press enter. This is effectively the Policies Editor, and it comes in handy often. For example, if you hate CD autoplay like I do and want to permanently disable it, you can use this tool to do so. Just run gpedit.msc, then go to Computer Configuration -> Administrative Templates -> System. In here you can see the value 'Turn Off Autoplay'. Right-click on it and then click 'Properties'.

Increasing options in add/remove programs:

Not a fan of MSN Messenger? don't want Windows Media Player on your system? Fair enough, but if you go to Add/Remove Programs in the Control Panel, by default none of Windows XP's 'built in' programs are visible. it's fairly easy to change, though... just open the file X:\Windows\inf\sysoc.inf (where X: is the drive letter where Windows XP is installed) in Notepad. You should see a section of the file something like this:

[Components]
NtComponents=ntoc.dll,NtOcSetupProc,,4
WBEM=ocgen.dll,OcEntry,wbemoc.inf,hide,7
Display=desk.cpl,DisplayOcSetupProc,,7
Fax=fxsocm.dll,FaxOcmSetupProc,fxsocm.inf,,7
NetOC=netoc.dll,NetOcSetupProc,netoc.inf,,7
iis=iis.dll,OcEntry,iis.inf,,7
com=comsetup.dll,OcEntry,comnt5.inf,hide,7
dtc=msdtcstp.dll,OcEntry,dtcnt5.inf,hide,7
IndexSrv_System = setupqry.dll,IndexSrv,setupqry.inf,,7
TerminalServer=TsOc.dll, HydraOc, TsOc.inf,hide,2
msmq=msmqocm.dll,MsmqOcm,msmqocm.inf,,6
ims=imsinsnt.dll,OcEntry,ims.inf,,7
fp_extensions=fp40ext.dll,FrontPage4Extensions,fp40ext.inf,,7
AutoUpdate=ocgen.dll,OcEntry,au.inf,hide,7
msmsgs=msgrocm.dll,OcEntry,msmsgs.inf,hide,7
RootAutoUpdate=ocgen.dll,OcEntry,rootau.inf,,7
IEAccess=ocgen.dll,OcEntry,ieaccess.inf,,7

This is a list of all components installed at the moment. I've taken the example of MSN Messenger - the program entry called 'msmsgs', third-last line. You can see the word 'hide' highlighted - this is the string which tells Windows not to display the component in the Add/Remove Programs list. Fix this up by simply deleting the word 'hide' like so:

msmsgs=msgrocm.dll,OcEntry,msmsgs.inf,hide,7

To this:

msmsgs=msgrocm.dll,OcEntry,msmsgs.inf,,7

Now, after restarting, you should be able to see MSN Messenger in the Add/Remove Programs list. If you want to be able to quickly view and remove all components, simply open the sysoc.inf file and do a global find and replace for the word ",hide" and replace it with a single comma ",".

Automatically Kill Programs At Shutdown:

don't you hate it when, while trying to shut down, you get message boxes telling you that a program is still running? Making it so that Windows automatically kills applications running is a snap. Simply navigate to the HKEY_CURRENT_USERControl PanelDesktop directory in the Registry, then alter the key AutoEndTasks to the value 1.

Speeding Up Share Viewing:

This is a great tweak. Before I found it, I was always smashing my head against the table waiting to view shares on other computers. Basically, when you connect to another computer with Windows XP, it checks for any Scheduled tasks on that computer - a fairly useless task, but one that can add up to 30 seconds of waiting on the other end - not good! Fortunately, it's fairly easy to disable this process. First, navigate to HKEY_LOCAL_MACHINE/Software/Microsoft/Windows/Current Version/Explorer/RemoteComputer/NameSpace in the Registry. Below that, there should be a key called {D6277990-4C6A-11CF-8D87-00AA0060F5BF}. Just delete this, and after a restart, Windows will no longer check for scheduled tasks - mucho performance improvement!

Create a Shortcut to Lock Your Computer

Leaving your computer in a hurry but you don’t want to log off? You can double-click a shortcut on your desktop to quickly lock the keyboard and display without using CTRL+ALT+DEL or a screen saver. To create a shortcut on your desktop to lock your computer: Right-click the desktop. Point to New, and then click Shortcut. The Create Shortcut Wizard opens. In the text box, type the following: rundll32.exe user32.dll,LockWorkStation Click Next. Enter a name for the shortcut. You can call it "Lock Workstation" or choose any name you like. Click Finish. You can also change the shortcut's icon (my personal favorite is the padlock icon in shell32.dll). To change the icon: Right click the shortcut and then select Properties. Click the Shortcut tab, and then click the Change Icon button. In the Look for icons in this file text box, type: Shell32.dll. Click OK. Select one of the icons from the list and then click OK You could also give it a shortcut keystroke such CTRL+ALT+L. This would save you only one keystroke from the normal command, but it could be more convenient.

Speed up Internet Explorer 6 Favorites

For some reason, the Favorites menu in IE 6 seems to slow down dramatically sometimes--I've noticed this happens when you install Tweak UI 1.33, for example, and when you use the preview tip to speed up the Start menu. But here's a fix for the problem that does work, though it's unclear why: Just open a command line window (Start button -> Run -> cmd) and type sfc, then hit ENTER. This command line runs the System File Checker, which performs a number of services, all of which are completely unrelated to IE 6. But there you go: It works.

Aspi

WinXP does not come with an Aspi layer. So far almost 90% of the problems with WinXP and CD burning software are Aspi layer problems. After installing WinXP, before installing any CD burning software do a few things first: 1. Open up "My computer" and right click on the CD Recorder. If your CD recorder was detected as a CD recorder there will be a tab called "Recording". On this tab uncheck ALL of the boxes. apply or OK out of it and close my computer. 2. Next install the standard Aspi layer for NT. Reboot when asked. That's is. after the reboot you can install any of the currently working CD recording applications with no problems. If using CD Creator do not install direct CD or Take two as they are currently incompatible but Roxio has promised a fix as soon as XP is released.

10 Security measures every PC user must do...........

Before you spend a dime on security, there are many precautions you can take that will protect you against the most common threats.

1. Check Windows Update and Office Update regularly (http://office.microsoft.com/productupdates); have your Office CD ready. Windows Me, 2000, and XP users can configure automatic updates. Click on the Automatic Updates tab in the System control panel and choose the appropriate options.

2. Install a personal firewall. Both SyGate (www.sygate.com) and ZoneAlarm (www.zonelabs.com) offer free versions.


3. Install a free spyware blocker. SpyBot Search & Destroy. SpyBot is also paranoid and ruthless in hunting out tracking cookies.

4. Block pop-up spam messages in Windows NT, 2000, or XP by disabling the Windows Messenger service (this is unrelated to the instant messaging program). Open Control Panel | Administrative Tools | Services and you'll see Messenger. Right-click and go to Properties. Set Start-up Type to Disabled and press the Stop button. Bye-bye, spam pop-ups! Any good firewall will also stop them.

5. Use strong passwords and change them periodically. Passwords should have at least seven characters; use letters and numbers and have at least one symbol. A decent example would be f8izKro@l. This will make it much harder for anyone to gain access to your accounts.

6. If you're using Outlook or Outlook Express, use the current version or one with the Outlook Security Update installed. The update and current versions patch numerous vulnerabilities.

7. Buy antivirus software and keep it up to date. If you're not willing to pay, try Grisoft AVG Free Edition (Grisoft Inc., www.grisoft.com). And doublecheck your AV with the free, online-only scanners available at www.pandasoftware.com/activescan and http://housecall.trendmicro.com.

8. If you have a wireless network, turn on the security features: Use MAC filtering, turn off SSID broadcast, and even use WEP with the biggest key you can get. For more, check out our wireless section or see the expanded coverage in Your Unwired World in our next issue.

9. Join a respectable e-mail security list, such as the one found at our own Security Supersite at http://security.ziffdavis.com or http://zone-h.org, so that you learn about emerging threats quickly and can take proper precautions.

10. Be skeptical of things on the Internet. Don't assume that e-mail "From:" a particular person is actually from that person until you have further reason to believe it's that person. Don't assume that an attachment is what it says it is. Don't give out your password to anyone, even if that person claims to be from "support."