Download Macro Viruses - Seminar Topics

Introduction
• Computer virus have become today’s headline
news
• With the increasing use of the Internet, it has
become easier for virus to spread
• Virus show us loopholes in software
• Most virus are targeted at the MS Windows OS
Definition of Virus
• A virus is a small piece of software that
piggybacks on real programs in order
to get executed
• A computer program usually hidden
within another seemingly harmless
program
• Once it’s running, it spreads by
inserting copies of itself into other
executable code or documents
Background
• There are estimated 30,000 computer
viruses in existence
• Over 300 new ones are created each
month
• First virus was created to show loopholes
in software
Effects of Computer Viruses
 It can destroy data and programs in computers.
 It effects any computer that opens the
seemingly harmless program.
 It effects schools.
 Viruses effect businesses.
 They also effect home computers.
Common Ways Viruses Spread
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Email attachments
Shared files
Floppy disks
Infected documents and infected word
processors
Important: Viruses almost never spread
between operating systems such as Mac
and Windows!
Types of Viruses
• File infectors
– Attach themselves to programs on infected
computers
– Virus runs when user runs a program
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Boot-sector infectors
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Attach to the “boot sector” of a disk
Virus activated whenever computer reboots
Macro viruses
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Attach to documents and spreadsheets
When user opens documents, virus spreads to
word processing programs
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Contaminates subsequent documents
Other Common Types of Viruses
 Worms
 Trojan Horses
 Macro
Worms
 Replicates itself
 Uses networks,
email, and the
Internet to infect
other computers
Trojan Horses
– Involves human interaction
– Users run the program intentionally, but it
does something more than user thought it
would
– Not a virus for it does not spread on it’s
own, but does have virus-like effects
Macro Viruses
What is a Macro?
A set of instructions commonly
found in Microsoft Word and other
programs
What is a macro virus?
A list of instructions that causes the
program to copy, delete, overwrite or
otherwise alter files, drop viruses or
execute programs
Spreading a Virus
DILLIP
DEBA
BABU
Friend
Friend
Friend
ARUNA
Friend
Friend
JYOTI
DIPTI
Friend
How Do I Know
If I Have a Virus?
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Some typical symptoms that may indicate a virus infection
include:
Virus checker gives a detected virus warning
Strange messages appear
Computer crashes more frequently
Strange files you do not recognize start appearing
Files get bigger or disk space disappears for no apparent
reason
Programs stop working as expected
I Think I Have a Virus!
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Don’t panic!
Stop using the computer
Write down any strange messages or warnings
Do not reboot, open files, or run programs
Run your virus scanner
Seek tech support help
Ways to Prevent Viruses
 Install a virus scanner
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Many are free
Keep it updated
Program it to run automatically
A few examples
 VirusScan
 AntiVirus
 F-Prot
 InnoculateIT
 Do not run programs found randomly on the Internet
 If you use Microsoft Word or Excel, disable macros
Prevention (continued)
 Only open expected email attachments
– Do not open anything from people you do not know
– If you are not expecting it, even from someone you
know, do not open it!
 Disable auto-run features in email programs
 Use Virus Scanner before opening downloaded
Internet files
 Keep your operating system and programs up-todate
 Turn off scripting in your web browser
Conclusion
 You know know more about virus and how:
– viruses work through your system
– to make a better virus
 Have seen how viruses show us a loophole in
popular software
 Most viruses show that they can cause great
damage due to loopholes in programming