Re: Storing passwords
From: Karl Levinson [x y] MVP (jamescagney90210@excite.com)
Date: 10/27/02
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From: "Karl Levinson [x y] MVP" <jamescagney90210@excite.com> Date: Sun, 27 Oct 2002 07:30:13 -0500
"Lem Lo" <lemlo@yahoo.com> wrote in message
news:ee0e01c27d84$6fdd14b0$36ef2ecf@tkmsftngxa12...
> Hello. I was wondering if anyone knew how the user and
> administrator passwords are stored? Is there a danger of
> someone being able to read them from a hard disk?
Yes, absolutely, though it probably requires special tools, the Windows
passwords themselves are generally not stored in plaintext unless you have
set the computer to log in as you automatically or you are using third party
software that uses passwords.
The passwords for Windows 2000 / XP / NT are stored encrypted in a file
called SAM [unless the computer is joined to a Windows 2000 Active Directory
domain, in which case some of the passwords are stored elsewhere].
L0phtcrack from www.l0pht.com is one of the more common cracking tools,
though there are other free ones. [along with PWDUMP / PWDUMP3 which is
used to dump the contents of the SAM] NTFSDOS from www.winternals.com can
be used for free to read the SAM file from an NTFS formatted hard drive if
someone has physical access to your computer [or if the hard drive is
formatted in FAT instead of NTFS, you just boot to a regular DOS boot floppy
to get the file]. There are also a number of boot disks that can be used to
blank out the administrator password to be able to log into your computer
without knowing the password.
On the other hand, depending on your environment, this may or may not be the
security issue you need to worry about most. Generally a lot of hacking is
done because a machine is missing the latest microsoft security patches or
is not configured securely.
More information can be found by searching www.google.com for SAM or any of
the other keywords here. The book Hacking Exposed 3rd edition is a good
introduction to a variety of security issues affecting Windows. There are
also a number of checklists on how to secure or harden Windows computers at
www.microsoft.com/technet/security, www.nsa.gov, http://rr.sans.org,
www.google.com, etc. Be sure to also secure IIS if IIS is installed.
Here's too much information, in case it is helpful:
==============
How can I harden my computer or server to secure it from
hackers?
A: [Note that if you have already been hacked, this
section will not help
you re-secure your computer. In this case, you should
first read the section
in this FAQ entitled "How can I re-secure my computer or
server after being
hacked?"]
Here is the short answer:
1. Do not put the computer onto the network or the
Internet until after the
computer has been hardened using the instructions below
[or at least not
before a firewall and antivirus have been installed].
2. Use firewall software and hardware and antivirus
software that is
configured to download updates every day;
3. Follow the instructions for hardening Windows and IIS
at
www.microsoft.com/technet/security ;
4. Install all service packs and security fixes from
Microsoft and otherwise
for all Microsoft software on your computer [Windows,
IIS, Office, Internet
Explorer, Windows Media Player, etc.] from
www.microsoft.com/technet/security ;
5. [Ongoing] Download MBSA from
www.microsoft.com/download and run it now
and also at regular intervals to look for vulnerabilities
in your settings,
new patches that are missing, etc. Also, check your
antivirus to confirm
that the last successful update was less than 14 days ago.
These steps will make your computer fairly secure, but
may still leave some
holes. Keep reading below for additional information you
should be aware of:
A successful hacker, virus or worm intrusion into one of
your computers can
drain your free disk space, slow down your Internet
connection, compromise
your credit card numbers, damage your personal documents,
allow intruders to
access other machines on your network that DO contain
important files,
and/or leave you legally liable for other government or
business computers
on the Internet that are hacked by an intruder using your
computer. This is
why you should consider securing ALL the computer systems
in your home or
network, even if you think there is nothing important on
the computer or it
is "just a test computer."
All Windows users should seriously consider all of the
procedures below to
help prevent intrusions on their computers:
1. Do not put the computer onto the network or the
Internet until after the
computer has been hardened using the instructions below.
[Un-secured
computers can be hacked in just 15 minutes or less after
being put onto the
Internet.] Depending on your environment, it may be
acceptable to put your
computer on the Internet after installing a firewall and
antivirus software
with the latest updates.
2. Seriously consider enabling or installing firewall
software and/or
firewall hardware. There are a number of free firewalls
available, including
the ICF feature that comes with Windows XP [unless XP is
joined to a Windows
domain], and/or other third-party firewalls available on
the Internet.
For more information on how and where to locate free and
not-free firewall
software and hardware, see the section in this FAQ
entitled "Which firewall
should I choose? Which firewall is the best?"
3. Seriously consider installing an antivirus program and
configure it to
automatically download updates daily.
For more information on where and how to locate and use
free and not-free
antivirus software, see the sections in this FAQ
entitled "Which antivirus
should I choose? Which antivirus is the best?" and the
section entitled "I
think I might have a virus / worm / Trojan."
4. Follow the instructions for hardening Windows 2000 and
also IIS [if IIS
is installed] at www.microsoft.com/technet/security [For
Windows 2000 / NT,
hardening IIS usually includes installing IISlockdown
including URLScan. For
computers with FTP service installed, it usually includes
removing the Posix
subsystem and removing write permission from the
anonymous user account,
among other things.]
5. Download and install all the service packs and
security patches from
www.microsoft.com/technet/security for all the Microsoft
and non-Microsoft
software installed on your computer, especially Microsoft
Windows, Office,
Internet Explorer, Outlook Express, Windows Media Player
and IIS [if IIS is
installed].
Note that Windows 2000, XP, .NET and NT users should also
download patches
for Indexing Services a.k.a. Index Server. Do not assume
that Index Server
patches are included with any IIS comprehensive service
pack rollup you may
already have installed, because they are not.
[If you want a shortcut to do this faster, you could try
this:
* Download and install the latest Windows service pack
from
www.microsoft.com/technet/security;
* Reboot and visit http://windowsupdate.microsoft.com to
receive additional
patches;
* Reboot, download and run MBSA [Microsoft Baseline
Security Analyzer] or
HFNETCHK from www.microsoft.com/download to discover
other missing patches;
* Manually download from
www.microsoft.com/technet/security and install any
patches that were found to be missing, as well as patches
for any server
products that may not be included in Windows Update and
MBSA/HFNETCHK, such
as possibly SQL Server, ISA Server, etc.
* NOTE however that Windows Update, MBSA and HFNETCHK do
NOT necessarily
list all Microsoft patches or search all Microsoft
products, so you could be
missing some patches if you rely just on these tools.]
6. [ONGOING] Re-run the MBSA tool from
www.microsoft.com/download every 60
days or sooner to look for missing patches, and confirm
that your antivirus
program received an update in the past 10 days or less.
If you want or need even more security [or are
particularly paranoid or at
risk], you can consider some of the additional steps
below. Some of the
tools below may be more security than you need, unless
you are running a
server such as IIS web or FTP services.
* Download and install MyNetWatchman or Dshield. These
are free programs
that work with your firewall software or hardware to
automatically report
hacking attempts to the hacker's ISP. You get to see
information about
whether that IP address has been used to scan or hack
other computers, or
whether it might be targeting just your computer. You
also get to see
whether the ISP has responded or taken action against the
offending user.
This is highly recommended. You can get this software at
one of the links
below:
www.mynetwatchman.com
www.dshield.org
* Sign up for the Microsoft security mailing list at
www.microsoft.com/technet/security to receive emails with
a link to new
critical security patches as they are released, and
install them ASAP.
* Use Fport or Vision from www.foundstone.com/knowledge
or pslist / pstools
from www.sysinternals.com to look at the open ports on
your computer and the
program or executable using that port. Some firewall
software such as
www.sygate.com will also tell you this information.
You can also use the NETSTAT -A command that comes with
Windows to look at
open ports; however, this will not identify which program
is using the port.
[You may want to run a command such as FPORT >>
C:\OPENPORTS.TXT or
PSLIST >C:\OPENPORTS.TXT or NETSTAT -A >>
C:\OPENPORTS.TXT
This command will create a "baseline" text file named
c:\openports.txt that
can be compared later with the results of the command to
tell you whether
additional ports are now open, a possible sign of
intrusion.]
* Consider running one or more vulnerability scanners to
look for security
flaws and configuration errors on your computers.
Vulnerability scanners
should be run after you have installed and hardened a new
computer or
server, and also run at regular intervals to confirm that
your computers are
still secure. You might also run a port scanner against
your computers as
well to look for open ports.
See the section in this FAQ entitled "How can I scan my
computer or firewall
to look for open ports or confirm that my machine is
secure?" for more
information.
* Consider searching for and following additional
checklists for hardening
Windows 2000 by searching an Internet search engine such
as www.google.com
for words such as "harden OR hardening windows-2000" [e.g.
www.google.com/search?q=harden+OR+hardening+windows-
2000 ]. Several such
checklists are available at
http://nsa1.www.conxion.com/win2k/download.htm
a.k.a. http://www.nsa.gov, as well as
www.labmice.net/security,
http://rr.sans.org, etc.
* Uninstall any unnecessary Windows components [e.g.
click on Start,
Settings, Control Panel, Add/Remove Programs, Add/Remove
Windows
Components]. Pay particular attention to Indexing
Service, Internet
Information Services (IIS), Management and Monitoring
Tools, Message Queuing
Services, Networking Services, Other Networking File and
Print Services,
Outlook Express, and Windows Media Player. If you are not
sure whether
something is unnecessary, try searching www.google.com or
posting a question
to the appropriate Microsoft security newsgroup.
* Disable any unnecessary Windows services [e.g. click on
Start, Settings,
Control Panel, Administrative Tools, Services]. If you
are not sure whether
something is unnecessary, try searching www.google.com or
posting a question
to the appropriate Microsoft security newsgroup.
* Consider using a Trojan scanner. Antivirus programs
generally detect some
but not all of the most common Trojans and hacker tools.
Some people choose
to use a Trojan scanner in addition to antivirus.
For more information on where and how to locate and use
free and not-free
Trojan scanner software, see the section in this FAQ
entitled "Which
antivirus should I choose? Which antivirus is the best?"
* Enable logging. Most logging is disabled by default,
and usually this is
not discovered until after an intrusion, when the logs
are needed.
Enable logging of your IIS web server, FTP server, etc.
For sites with a
small number of hits, consider changing logs to rotate
monthly instead of
daily to allow easier searching of logs.
Enable logging on your Internet router, switch or
firewall. [Because these
devices usually do not have much storage space for saving
logs, doing this
may involve installing free syslog software onto your
computer to be able to
capture the logs.]
Enable auditing of security events on your Windows
system, including logon
successes and/or failures and NTFS auditing of files and
registry keys. For
more information, see the section in this FAQ
entitled "How can I enable
auditing / logging on my computer / server?"
Change the Windows event log settings to be appropriate
for your
environment. Consider increasing the maximum log size to
retain more
information. Be careful not to log too much, or you might
find that your
logs contain only a few minutes or hours worth of data.
Check the logs to be sure logs are really being captured.
* Consider using a file change checker, such as the
unsupported free tool
Languard File Integrity Checker at
www.gfi.com/languard/lantools-fic.htm
Files changing on your system can sometimes indicate a
hacker intrusion.
* Consider using a Windows event log monitor. Some types
of intrusions leave
entries in one of the logs on your computer. [On an
especially vulnerable or
secure system, you should be sure that you've configured
logging to detect
events such as intrusions.] Some network monitors such as
www.ipsentry.com
can send a message to your email/screen/pager if a server
or service stops
responding, an event or error appears in a Windows log,
etc. Windows log
monitors can be found by searching an Internet search
engine or your
favorite software web site, or by using the links below:
www.ipsentry.com [around $100 US]
www.sunbelt-software.com
www.webattack.com
www.wilders.org
www.download.com
www.tucows.com
www.google.com/search?q=windows+event+log-monitor
* Consider using EFS file encryption [under Windows
2000 / XP / .NET] or
third-party utilities to encrypt the files on your
computer may be something
to consider. Some of these utilities can encrypt your
entire hard drive
including Windows, whereas other tools just encrypt some
of your data files
and are not suitable for encrypting or preventing access
to Windows.
Note that using any form of encryption can slow down your
computer's
performance. Also, you must be extremely careful to back
up and protect your
encryption key and any passwords. If the encryption keys
are not backed up,
users can lose their encrypted files forever when Windows
is reinstalled,
Windows encounters a problem so that Windows no longer
starts up, etc.
For more information on EFS file encryption on Windows
2000 / XP / .NET, see
the section in this FAQ entitled "I used Windows 2000 /
XP EFS file
encryption to encrypt some files. Now, I can't read the
files. How can I
unencrypt them or recover the key?"
Third party encryption software can be found at the
following locations:
www.pgp.com
www.scramdisk.clara.net
www.e4m.net
www.jetico.com ["BestCrypt"]
www.download.com
www.tucows.com
www.google.com
________________________________________________________
Which antivirus should I choose?
The best way to deal with any virus on any computer or
server is ALWAYS to
install and use an antivirus program that is updated with
the latest updates
for that week [or day].
Some antivirus manufacturers may release mini-tools that
will remove a
particular virus or worm, such as a Nimda virus removal
tool. However, these
single-virus removal tools generally do nothing to
protect you from becoming
re-infected when you receive another infected email or
file five minutes
after you ran the tool. Antivirus software is necessary
to prevent against
re-infection and damage to your computer files.
Just running an antivirus program is not enough. You
should make sure that
your antivirus program can be configured to download
updates every day [or
every week] automatically via the Internet, and open the
program from time
to time to ensure that it is still receiving updates.
NOTE however that if an antivirus scanner or Trojan
scanner finds a Trojan
installed and running on your computer, it could be a
sign of a hacker
intrusion, in which case you will want to consider taking
additional steps
before removing the Trojan. For more information, see the
section in this
FAQ entitled "How can I tell if I've been hacked?"
If you have a particular file name and wish to find out
whether or not it is
a virus [or a worm, a Trojan, a hoax, etc.], you can try
searching an
Internet search engine such as www.google.com for that
file name. However,
it is still best to install and use an antivirus scanner.
Looking up a
particular file name is NOT a reliable way to determine
whether or not the
file is a virus.
Deleting a file from your system is never the first way
or the best way to
try to remove a virus from your computer.
Which antivirus software is best for you will vary
depending on your
computer systems, your security requirements and your
personal preferences.
Antivirus programs may be purchased from Internet web
sites, from your local
computer store, and even from stores like Target and Wal-
Mart. Antivirus
software can be found using the links below:
www.symantec.com [Norton Antivirus]
www.grisoft.com [AVG Antivirus [including a free version]
www.f-prot.com/products [free DOS version]
www.f-secure.com [F-Secure]
www.trendmicro.com [Trend Micro]
www.wilders.org
www.download.com
www.tucows.com
[Most of the antivirus products will also work on Windows
Server products or
have a version for Windows Server.]
There are also a number of web sites that will scan your
computer for
viruses for free. However, using these web sites will do
nothing to protect
you against future re-infection and damage to your
computer files. Some of
these web sites include:
http://security2.norton.com [Norton free one-time web-
based scanner]
http://housecall.antivirus.com [Trend Micro free one-time
web-based scanner]
Just running an antivirus program is not enough. You
should make sure that
your antivirus program can be configured to download
updates every day [or
every week] automatically via the Internet, and open the
program from time
to time to ensure that it is still receiving updates.
Antivirus software is like prescription drugs or
psychologists; the first
one you get might not work right for you. If one
antivirus program fails to
install or causes your computer to perform slowly, you
could contact the
manufacturer, or you could uninstall it and try another
antivirus program.
Note that you may need to set your antivirus program to
ignore certain
folders, such as the folder containing your firewall
software. Failing to do
so can cause speed problems or false alarms on your
computer.
You generally only want to install and run no more than
one antivirus
program on your computer at a time. Running two memory-
resident, on-access
antivirus programs simultaneously can cause false alarms
or cause other
problems.
If you are running antivirus with the latest updates and
are STILL having
problems removing the virus, you should:
* Note the name of the virus being reported by your
antivirus program;
* Visit the web site for your antivirus manufacturer and
click on "Support,"
so that you can:
+ Look up the virus name in the virus information
database for info and
follow any instructions found there;
+ Search the support web page for your antivirus; and/or
+ Post a question in the support group for your antivirus.
For example, if you are using Norton Antivirus, you
should visit the
following web sites:
www.sarc.com - NAV virus database
www.sarc.com/techsupp - free NAV support discussion groups
Be wary of any email ever that:
* Tells you to delete a file from your computer as the
first or only way to
remove a particular virus;
* Tells you to forward the email to everyone you know;
* Tells you that a particular virus cannot be stopped by
antivirus.
* Tells you that a particular virus has been confirmed by
a large company or
government entity, such as Microsoft, IBM, the Department
of Defense, etc.
Emails such as the ones described above are usually
hoaxes [even if the
warning email is from a friend that you trust]. Stop and
confirm or have
someone confirm the authenticity of any warning email
before forwarding it
to anyone. You can often confirm or deny the existence of
a particular virus
by searching for the virus name at an Internet search
engine or virus
manufacturer's web page, such as:
www.google.com
www.sarc.com - Norton Antivirus
www.f-secure.com/virus-info - F-Secure
TROJAN SCANNERS:
It is also a good idea to consider using a Trojan scanner
*in addition to*
antivirus software. Trojans and hacker tools can cause
many of the same
symptoms that viruses and worms do, but antivirus
programs generally do not
detect all of the most common Trojans and hacker tools.
Some Trojan scanners
can be found by searching an Internet search engine or
your favorite
software web site, or by using the links below:
www.pestpatrol.com [includes a free mini-scanner]
www.lockdowncorp.com
www.wilders.org
www.download.com
www.tucows.com
www.sunbelt-software.com
www.google.com/search?q=trojan-scanner
When looking for Trojans, you should also consider using
a tool to look for
open ports, such as Vision or Fport from
www.foundstone.com/knowledge or
Pstools / Pslist from www.sysinternals.com
For more extensive information about looking for Trojans,
backdoors and
other hacker tools, see the section in this FAQ
entitled "How can I tell if
I've been hacked?"
====================
Which firewall should I choose? Which firewall is the
best?
A: The answer to this question varies depending on your
computer systems,
your security requirements and your personal preferences.
Below are some
firewalls and other forms of firewall-like packet
filtering:
NO MATTER WHICH FIREWALL YOU CHOOSE...
No matter which firewall you choose, you should seriously
consider
downloading and installing MyNetWatchman or Dshield.
These are free programs
that work with your firewall software or hardware to
automatically report
hacking attempts to the hacker's ISP. You get to see
information about
whether that IP address has been used to scan or hack
other computers, or
whether it might be targeting just your computer. You
also get to see
whether the ISP has responded or taken action against the
offending user.
You can get this software at one of the links below:
www.mynetwatchman.com
www.dshield.org
Also, no matter which firewall you choose, the lists
below of port numbers
for common software services may be helpful when
configuring your firewall
or when trying to monitor the firewall logs for signs of
intrusion:
www.iana.org/assignments/port-numbers
www.iisfaq.com/default.asp?View=P106
FIREWALL SOFTWARE:
www.sygate.com [free for non-commercial use, also works
like a sniffer]
www.kerio.com [free for non-commercial use]
www.agnitum.com [free for non-commercial use]
www.zonealarm.com [free for non-commercial use, also
blocks pop-ups]
www.iss.net [Black Ice]
www.symantec.com [Norton]
www.webattack.com
www.download.com
www.tucows.com
[Windows XP users can also consider using the ICF
firewall that comes with
XP, more info below]
FIREWALL DEVICES [HOME / SOHO]:
www.linksys.com [starts around $70 US]
www.netgear.com [starts around $70 US]
http://search.ebay.com/search/search.dll?query=firewall
[prices on new and
used firewalls]
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