Viruses, Hacking, and AntiVirus
What is a Virus?
• A type of Malware
– Malware is short for malicious software
• A virus – a computer program
– Can replicate itself
– Spread from one computer to another
First Viruses
• Creeper Virus detected on ARPANET
• Would display “I'm the creeper, catch me if
you can!“
• “Elk Cloner” – attach to Apple DOS 3.3 OS and
spread via floppy disk
Types of Viruses
• Viruses that infects popularly traded software
• Macro Viruses: written in scripting languages
for Microsoft programs such as Word and
Excel
• Viruses in Executables
How Your Computer Gets Infected
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Binary Executable files (DLL’s, EXE’s)
An external, physical device
General Purpose Script files
System Specific Autorun Script files
Documents that contain Macros
Exploitable bugs in a program
Links to malicious code in PDFs, HTML, other
documents
An Example
• A file could be named “picture.png.exe”
• When opened, the program runs and infects
computer
• Spoofing an email address to make it sound
legitimate so you’ll download and open an
attachment
Malware
• Includes viruses, worms, trojan horses,
spyware, adware
Purpose of Malware
• Used to steal personal, financial, or business
information
• Destroy data
• Hijacking computers for various purposes
Cookies
• Cookies are small files deposited on a system
during a web site visit
• Can be useful:
– Allows web servers to maintain state (position and
information) of a session with a user
– Can keep track of your login information, shopping
cart, etc.
• May be harmful
– Allows web sites to track information unbeknownst to
user
– Source of data for Pop-ups
Worms
• Worms are similar to viruses in the way they
are spread
• Doesn’t need user action to spread
• Actively transmits itself over networks to
infect other computers
Trojan Horses
• A program that looks like a harmless program
but contains malicious code
• Used to install other malware such as
backdoors or spyware
Rootkits
• Rootkits: modify OS so malware is hidden
• “Each ghost-job would detect the fact that the
other had been killed, and would start a new
copy of the recently stopped program within a
few milliseconds. The only way to kill both
ghosts was to kill them simultaneously (very
difficult) or to deliberately crash the system.”
Backdoors
• A way to bypass normal authentication
procedures
• Example: a hard coded user and password
that gives access to a system or computer
• Easter Eggs
• Many viruses and worms attempt to create
backdoors for more viruses
Spyware
• Software that monitors and gathers information
about your system or computing
• Can collect personal information, Internet surfing
habits, user logins, bank or credit account
information
• Can change computer settings
• Keyloggers – collects information about what you
type
• Port Sniffers – intercept and log data sent over a
network
Port Scanners and Sniffers
• Port Sniffers – intercept and log data sent over
a network
• Port Scanner – software that probes a server
or computer network for
open ports. Use ports
to access network.
Bots and Botting
• Programs that take control of a computers normal
operation, or operate in stealth mode on a computer
• Can be used to disrupt normal operations
• Can turn a user’s computer into a source of malware
attacks on others
(Email Spamming)
Adware
• Advertising-supported software: automatically
renders unwanted advertisements
• Object is to generate revenue for its author
Non-Malware, Active Threats
• Phishing – Posing as a trustworthy entity to
acquire information
• Fake websites
• Email Spoofing
Non-Malware, Active Threats
• (Distributed) Denial of Service, AKA DDOS
attack
• Flooding a web server with spurious traffic
generated to overwhelm the server’s
capabilities thus denying legitimate users or
exposing system flaws
• Related to Botting
Scareware
• Holds your PC hostage
Hacking
USES ALL OF THE ABOVE
Not this:
http://www.youtube.com/watch?v=u8qgehH3kEQ
Additional Hacking
• Password Cracking
• Software bugs: buffer-overrun, SQL Injections
• http://hackertyper.com/
• http://en.wikipedia.org/wiki/Stuxnet
Protecting Your Computer
Signs Your Computer May Be Hacked
• Your computer is running slow
• Processes you don’t recognize are running
• You are asked for personal information via
email, or by phone
• You see data or programs disappear or change
• A Pop-up says your machine is infected and
you need to scan it right now – and it is not
the security software you installed
Anti-Spyware
• When a large number of pieces of spyware
have infected a Windows computer, the only
remedy may involve backing up user data, and
fully reinstalling the OS.
1. Scans incoming network data for spyware
2. Detects and removes spyware
Firewalls
• Similar to Anti-Spyware but controls all
incoming and outgoing traffic and what should
and shouldn’t be allowed in and out
Anti-Virus
Pros:
• Prevents, detects and removes malware
Cons:
• False Positives, False Negatives
• Slows down your computer
Be Smart!
• Don’t open emails that you don’t recognize
• Don’t download attachments you don’t
recognize
• Don’t run programs or install applications you
don’t know or trust
Personal Checklist
Passwords are set, sufficiently complex, and not shared
Legitimate Anti-Malware software running
Home wireless network protected by WPA
Firewall software running
Browser settings appropriate
Sensitive files are protected - password and encrypted
Smartphone protected – locate, lock, wipe
Software is kept up to date
I'm being cautious:
- Which web sites I visit
- When I open emails
- Where I leave my laptop, smartphone, USB drive
- When asked for information via email, internet, phone
- When I use public wireless networks
- When I download applications
Some Anti-Virus Software
• http://anti-virus-softwarereview.toptenreviews.com/
• http://www.techsupportalert.com/best-freeanti-virus-software.htm
Some Anti-Virus Software
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Avast!: http://www.avast.com/en-us/index
Avira: http://www.avira.com/en/index
AVG: http://www.avg.com/us-en/homepage
Microsoft Security Essentials:
http://windows.microsoft.com/enUS/windows/security-essentials-download
• MalwareBytes:
http://www.malwarebytes.org/