Viruses, Worms, and
Hackers: Protect Your
Personal Computer
“Just Minutes to the Internet”
“The iMac is the quickest way to
get on the Internet. It’s so easy to
set up and use, you’ll be online and
surfing the web in minutes…”
-http://www.apple.com/imac/
The Problem….
 There is a tradeoff between ease of use and
security for computers
 To sell more products, companies have to make
computers easy to use.
 However, today’s powerful computers plugged
into the internet shouldn’t be treated like any other
new household appliance.
The Even Greater Problem…
 The Internet is being scanned constantly by
self-replicating worms and deliberate
attacks.
 Hackers want to exploit computers with lax
security to take advantage of hard drive
space and relatively fast connections.
Common Security Problems for
Home Machines
 May include:
– privacy invasions
– backdoor/trojan infections where an unauthorized
person remotely has complete control of your computer.
– virus and worm infections,
– spyware
– warez (file-trading) servers installed,
– your computer is used to attack other computers
– destruction of files (data, operating system, etc)
Am I at Risk at home? Why?
 Cable modems / DSL: have a fast, always on
connection that hackers can return to again and
again. This atmosphere also provides a good
breeding ground for self-replicating worms.
 “Camping out” on a modem: keeping the same IP
address allows hackers to scan your system and
return at a later date to infect it.
 Short dial up modem sessions: Occasionally,
security incidents occur on dial-up machines with
both worms and “hacking” incidents.
How to Make Your Home
Machine As Secure As at Work
 Make sure your computer has good strong
passwords
 Patch your machine regularly
 Install an anti-spyware product
 Use an anti-virus product and update it regularly
 Use a router-based firewall Know what is running
on your system
 Use good internet hygiene
Make Sure Your Machine Has
Good Passwords
 Most operating systems require a password to
protect your computer from unauthorized access.
 Passwords should not be dictionary words and
should consist of 7+ characters of mixed case
including numbers, letters, and symbols.
 Some guidelines for selecting – and remembering
– a strong password can be found at:
http://www.alw.nih.gov/Security/Docs/passwd.htm
l
Operating System Password
Requirements
 Windows:
– Passwords required for Windows XP Pro and Home
versions, Windows 2000, and Windows NT.
• Note: With Windows XP Home edition you may have to boot
into “Safe mode” to assign an administrator password
– Passwords not necessary for Windows 95, 98, or ME.
 Linux / Unix:
– Passwords required for all flavors.
 Macintosh:
– Passwords required
Patch Your Machine Regularly
 Computer software vendors provide regular updates
for their products that can protect against known
security vulnerabilities. These updates are called
patches.
 Use automatic updates where possible (e.g. Windows
Update) or download updates from vendors. Try to
download major / “critical” patches to removable
media such as CD and install them before putting your
computer on the Internet for the first time.
 When you hear of a new major vulnerability or patch,
try to install it as soon as possible.
Automatic Updates of MS
Windows Operating Systems
 All Windows OS patches can be accessed here:
http://v4.windowsupdate.microsoft.com/en/default.asp
 You can set up your Microsoft operating system to
check for updates automatically
– Using Windows 2000 and Windows XP:
Click on the Start button > Control Panel > System
– Using Windows 98 and Me:
Click on Start > Control Panel > Automatic Updates
The Windows ME Control Panel with
Automatic Updates highlighted
Automatic Updates of MS
Windows Operating Systems
 Using Windows 2000
or XP, select System
then click on the
Automatic Updates tab
 Be sure the check box
near the top is checked,
then select the radio button
which suits you.
 Using Windows 98 or Me
select the Automatic Updates
icon (this next screen
Protect Your Machine From
Spyware (Adware)
 Spyware: software that is installed on a computer
without the user’s knowledge which monitors user
activity and transmits it to another computer.
 Many spyware programs are set to monitor what
web sites you visit and how long you visit them
for, generally for advertising / marketing purposes
(adware).
How Would I Get Spyware
Installed On My Machine?
 Spyware is usually bundled with other software
such as shareware or freeware programs (e.g. Peer
to Peer file-sharing programs, games, etc). The
disclosure for the spyware is usually in the fine
print of the licensing agreement. Who reads these
anyway?
 Another way to get spyware on your machine is
by clicking on a deceptive pop-up message.
Consequences of Spyware
 Spyware runs in the background, using your
computer’s system resources and memory to log
what you are doing. This could interfere with
other programs on your computer, and could even
cause your computer to frequently crash or lock
up.
 Spyware also uses your internet connection to
send information about your activities to someone
else. This could cause your internet connection to
slow significantly.
Malware, Viruses, and Worms
 Malware is software which has malicious
intent that is usually installed without the
owner’s knowledge. Malware may be
disguised to look like benevolent software.
Malware, Viruses, and Worms
 Viruses are small programs which cause some
unexpected event on a computer and automatically
spread to other computers via e-mail, open file
shares, and programs installed on the computer
(e.g. Kazaa, AOL Instant Messenger, etc).
 Worms are self-replicating viruses that are loaded
into computer memory rather than altering files on
the machine. A worm’s main goal in life is to
spread to as many other machines as possible.
Examples of Malware
 One example would be a virus that has a
“backdoor” installed. This means that someone
at a remote location has total control of your
computer. That person can modify or add files to
your computer, install programs, add user
accounts, or even delete all of your files!
 Another example is a “keylogger”, which records
every stroke you enter into your keyboard. The
keylogger may record a wealth of information:
credit card information, passwords, chat room
transcripts, private e-mail messages, etc
Scared Yet? Protect Your
Privacy!
 Install software to detect and remove spyware,
adware, and malware
 Adaware
– http://www.lavasoftusa.com/software/adaware/
 Spybot S&D
– http://www.safernetworking.org/index.php?page=download
Keep Your Anti-virus Program
Up to Date
 Update virus definitions weekly, or more often if
you hear of a new virus
 Set virus protection to automatically download
virus definition updates if possible.
 Perform a full virus scan of your hard drive(s) at
least monthly (if not more often)
Install a Personal Firewall
 A personal firewall is a software-based filter between your
computer and the outside world that is installed on your
computer to protect it from unauthorized access by other
external users.
 Personal firewalls are configurable to specify which incoming
and outgoing programs, ports, and IP addresses can be accessed.
 Recommended personal firewalls that are free for personal use:
– Zonealarm
• http://www.zonealarm.com
– Tiny Personal Firewall
• http://www.tinysoftware.com
Inexpensive Routers with BuiltIn Firewalls
 A firmware or hardware based firewall is a separate device
that physically sits between your computer and internet
connection.
 This type of firewall is generally more secure than a personal
firewall and saves processing time on the computer that the
personal firewall would otherwise be using.
 Router-based firewalls can range in price from relatively
inexpensive ($70) to thousands of dollars.
 This type of firewall device is highly recommended for home
use and can protect many types of connections including dialup
modem, cable modem, DSL, etc.
Two Inexpensive Router-based
Firewalls
 Linksys Cable/DSL Router ($60)
is for Cable/DSL and quite usable for home use (1
to 4 ports).
 SMC 7004ABR ($80):
This is for Cable/DSL and also has an RS-232 port
(for Internet connection via modem).
Know What Is On Your System
 You should periodically determine what all of
your running processes are on your computer,
and if they are valid.
 You can analyze what processes are on your
Windows system by downloading a tool such
as TCPView, Fport, Inzider, or Active Ports.
 On a unix system, you can analyze running
processes by typing the command “lsof”.
Prevent Identity Theft When
Making Online Purchases
 Look for a padlock at the bottom of web pages,
indicating that the site is secured by encrypting
data when submitting sensitive information such
as credit card numbers or a SSN.
 A secure site means that your data is encrypted
during transmission. Keep in mind that it says
NOTHING about how secure the data is once it is
stored on a remote computer.
Prevent Identity Theft When
Making Online Purchases
 Purchase from well-known companies
(Don’t buy from mass e-mail solicitation)
 Realize that reputable web sites will never
e-mail request for any personal information
such as SSN, password, credit card or bank
acct. number, etc.
Use Good Computer Hygiene
 “Think before you click”
– Be careful with e-mail attachments – call or write back
to confirm before opening
– Be careful about what web sites you go to.
– Be careful when prompted to download software
 Use good passwords and change them periodically
for both machine and web sites you visit!
 Don’t create non-password protected file shares
 Backup data frequently
 Remove internet access when it is not needed
 Install minimal applications and services
To Review….
 There are a lot of simple steps you can take to
keep your computer secure and free of intruders.
These include:
– Using “good” passwords
– Patching your computer
– Installing anti-virus, anti-spyware, and firewall
products
– Using a VPN to encrypt network traffic to Penn State
– Knowing what is running on your computer and turning
off unnecessary software
– Using good internet hygiene and purchasing habits
 Remember, it is a lot easier to be proactive than to
attempt to “clean up” later.
Personal Computer Security
Checklist
 A step-by-step checklist, written by a computer
security expert, for securing your personal
computer can be found at:
http://securityfocus.com/columnists/220
 We encourage that you reference the above
checklist, as well as follow recommended steps in
this presentation.
Questions?