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 and TCP/IP packets Love Bug Some flood network with useless traffic causing Denial of Service attacks

How Viruses Spread Shared files attachments –Usually have.exe extensions –Cannot infect you if you don’t open them –Two extension filenames highly suspect 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 s 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 containing dire warnings Strategy to avoid the virus Recommends ing 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 folders address book Favorite URLs Downloads Windows Registry

Backup Procedures Full backup: all files Differential backup: only files added/changed since last full backup Incremental backup: only files added/changed since any backup

Backup Hardware and Media Tape Drives: best for PCs –Inexpensive –Can hold entire hard drive –1 GB in 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 123

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