Transcript Computer Concepts 161-186 - Scott Marino`s personal Web Site

Data Security
Unit F
Objectives
Know What Can Go Wrong
Explore Data Security Issues
Introduce Computer Viruses
Understand How viruses Spread
Restrict Access
Use Antivirus Software
Objectives
Introduce Data Backup
Examine Backup Procedures
Explore Backup Hardware and
Media
Explore Backup Strategies
Explore Backup Software
What Can Go Wrong
Operator errors
– Direct source input device (scanners)
Software errors
Power Failures
– Power spike
– Power surge
– UPS (Uninterruptible Power Supply)
– Surge strip vs. power strip
– Unplug during storm
Data Security Issues
Hardware failure: data
loss possible
MTBF: mean time
between failures is a
reliability measurement
Physical damage from
smoke, fire, water,
breakage, theft
Data vandalism like
viruses and hackers
How You Can Protect Yourself
Data security are the techniques
that provide protection for your
data
Risk management is the process
of weighing threats to computer
data vs. the amount of expendable
data and the cost of protecting
crucial data
Disaster Recover Centers provide
emergency computing facilities
Computer Virus
A set of program instructions
that attaches itself to a file,
reproduces itself and
spreads to other files.
Computer Virus – It’s a CRIME!!
Trigger event (payload) often
keyed to specific date
Can be classified by types of files
they infect:
– File virus (games)
– Boot sector virus (system files)
– Macro virus (applications)
Trojan Horse
A computer program that seems
to perform one function while
actually doing something else.
Good at stealing passwords
Worms
Designed to spread from
computer to computer
Travels within e-mail and
TCP/IP packets
Love Bug
Some flood network with
useless traffic causing
Denial of Service attacks
How Viruses Spread
Shared files
E-mail attachments
– Usually have .exe extensions
– Cannot infect you if you don’t open them
– Two extension filenames highly suspect
E-mail messages
– HTML format can spread them
Web site downloads
Macro viruses in attachments or files
on disk
Virus Symptoms
Vulgar/annoying messages displayed
on computer
Unusual visual or sound effects
Difficulty saving files or files disappear
Computer very slow
Computer reboots unexpectedly
Executable files increase in size
unaccountably
Computer sends out emails on its own
Restricting User Access
Physically
– Restrict access to computer area
– Keep backup disks in locked vault
– Keep offices locked
– Keep computer case locked
Restrict data access to
authorized users
– Passwords
– User rights
Restricting User Access
Personal identification
– Something a person carries (badge)
– Something a person knows (IDs and
passwords)
– Some unique physical trait (biometrics)
Fingerprint
Scanner
Retinal
Scanner
Antivirus Software
A set of utility programs that
looks for and eradicates a
wide spectrum of problems,
such as viruses, Trojan
horses and worms.
Antivirus Protection Methods
File length
Checksum
Virus signature
Viruses Escape By:
Multi-partite viruses infect
multiple target types
Polymorphic viruses
mutate by changing
signature
Stealth viruses remove
their signatures
Retro viruses attack
antivirus software
Other Virus Issues
Keep antivirus software
running full-time in
background
Easier to keep virus out than
to eradicate it
Keep your software updated
with new versions
Not 100% reliable
Virus Hoaxes
E-mail containing dire
warnings
Strategy to avoid the virus
Recommends e-mailing
friends
Usually have long list of
people in To: and CC: boxes
Recommends dangerous
procedure for eradicating virus
Data Backup
Backup: copy one or more
files in case the original files
become damaged
Restore: copy the backup
files back onto a hard disk
Full vs. partial backups
Software files vs. data files
Keep all data files in My
Documents
Important Files to Backup
Internet connection data
E-mail folders
E-mail address book
Favorite URLs
Downloads
Windows Registry
Backup Procedures
Full backup: all files
Incremental backup: only files
added/changed since any backup
Differential backup: only files
added/changed since last full backup
Backup Hardware and Media
Tape Drives: best for PCs
– Inexpensive
– Can hold entire hard drive
– 1 GB in 15-20 minutes
Floppy disks, Zip disks
Writable CDs and DVDs: slower than
tape
Second hard disk drive: least reliable
Remote storage on network for a fee
Backup Strategies
Run up-to-date antivirus
software before backing up
Create a boot disk
– Recovery CD from computer
manufacturer
– Windows Startup Disk
– Rescue disk created from antivirus
software
Backup Strategies
Decide on storage medium
Make rotating sets of backups
Test backups
Store backups in safe place
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Backup Software
Copy Disk utility via operating
system
Backup software from
– Windows, Accessories, System Tools
– Supplied with backup devices
Keep original backup software
CD
TechTalk: Securing a LAN
Password protection
Personal firewall software
that analyzes and controls
incoming/outgoing packets
Network address translation
(NAT): using private IP
addresses within LAN
TechTalk: Securing a LAN
DOCSIS (Data Over Cable
Service Interface
Specification) filters packets
to certain ports
Disable file and print sharing
Shut down the computer
when not in use
Issue: Is It a Crime?
Data Security
End