Introduction
Data and information must be protected against unauthorized access, disclosure, modification or damage.
14) Size of executable files changing for no obvious reason.
Control measures against viruses.
1. Install up-to-date antivirus software on the computers.
2. Restrict the movement of foreign storage media, e.g., disk in the computer room. If they have to be used, they must be scanned for viruses.
3. Avoid opening mail attachments before scanning them for viruses.
4. Write-protect disks after using them.
5. Disable disk drives (ports), if there is no need to use disks in the course of normal operation.
6. Backup all software and data files at regular intervals.
7. Do not boot your computer from disks which you are not sure are free from viruses.
8. Avoid pirated software. If possible, use the software from the major software houses.
2). Unauthorized Access
Data and information is always under constant threat from people who may want to access it without permission.
Data and information must be protected against unauthorized access, disclosure, modification or damage.
This is because; it is a scarce and valuable resource for any business organization or government.
It is mostly used in transactions, it can be shared, and has high value attached to it.
Data security is the protection of data and information from accidental or intentional disclosure to unauthorized persons.
Private data or information is that which belongs to an individual and must not be accessed by or disclosed to any other person, without direct permission from the owner.
Confidential data or information; this is data or information held by a government or organization about people.
Private data or information is that which belongs to an individual and must not be accessed by or disclosed to any other person, without direct permission from the owner.
Confidential data or information; this is data or information held by a government or organization about people.
This data/information may be seen by authorized persons without the knowledge of the owner.
However, it should not be used for commercial gain or any other unofficial purpose without the owner being informed.
Security Threats to Data & Information
1). Computer Viruses
1). Computer Viruses
A computer virus is a destructive program that attaches itself to other files when the files are opened for use, and installs itself on the computer, without the knowledge of the user.
A computer virus is a program designed specifically to damage other programs or interfere with the proper functioning of the computer system.
A virus is a computer code usually designed to carry out 2 tasks:
(a) To copy itself from one computer system to another.
(b) To locate itself within a computer system enabling it to amend/destroy program & data files, by interfering with the normal processes of the operating system.
Types of computer viruses.
1. Boot sector viruses they destroy the booting information on storage devices.
2. File viruses; they attach themselves to files either erasing or modifying them.
3. Hoax viruses; they come as e-mails with an attractive subject and activate themselves when the e-mail is opened.
4. Trojans; they appear to perform necessary functions, but perform other undesirable activities in the background without the knowledge of the user.
5. Worms; viruses that stick in the computer memory.
6. Back doors maybe a Trojan or Worm that allows hidden access to a computer system.
Types of destructions/damages caused by a virus attack
1. Delete or modify data, information and files on storage devices (disks) or memory during normal program execution, e.g., may attack the format of a disk making any program or data on it impossible to recover.
2. Systematically destroy all the data in the computer memory.
3. Might lock the keyboard.
4. Can change keystroke values or data from other I/O devices, e.g., change the effect of SHIFT key.
5. Delete characters displayed on a visual display.
6. Uses up computer memory/space, hence slowing down its performance or causing the system to crash.
7. Changes colour of the display.
8. Cause boot failure.
Sources of viruses.
a) Contact with contaminated systems
If a disk is used on a virus infected computer, it could become contaminated. If the same disk is used on another computer, then the virus will spread.
b) Use of pirated software
Pirated software may be contaminated by a virus code or it may have been amended to perform some destructive functions which may affect your computer.
c) Infected proprietary software
A virus could be introduced when the software is being developed in laboratories, and then copied onto disk containing the finished software product.
d) Fake games
Some virus programs behave like games software. Since many people like playing games on computers, the virus can spread very fast.
e) Updates of software distributed via networks
Viruses programs can be spread through software distributed via networks.
Symptoms of viruses in a computer system.
The following symptoms indicate the presence of a virus in your computer;
1) Boot failure.
2) Files and programs disappearing mysteriously.
3) Unfamiliar graphics or messages appearing on the screen, e.g., the virus might flash a harmless message such as "Merry Christmas" on the computer terminal.
4) Slow booting.
5) Gradual filing of the free space on the hard disk.
6) Corruption of files and programs.
7) Programs taking longer than usual to load.
8) Disk access time seeming too long for simple tasks.
9) Unusual error messages occurring more frequently.
10) Frequent read/write errors.
11) Disk access lights turning on for non-referenced devices.
12) Computer hangs anytime when running a program.
13) Less memory available than usual.
(a) To copy itself from one computer system to another.
(b) To locate itself within a computer system enabling it to amend/destroy program & data files, by interfering with the normal processes of the operating system.
Types of computer viruses.
1. Boot sector viruses they destroy the booting information on storage devices.
2. File viruses; they attach themselves to files either erasing or modifying them.
3. Hoax viruses; they come as e-mails with an attractive subject and activate themselves when the e-mail is opened.
4. Trojans; they appear to perform necessary functions, but perform other undesirable activities in the background without the knowledge of the user.
5. Worms; viruses that stick in the computer memory.
6. Back doors maybe a Trojan or Worm that allows hidden access to a computer system.
Types of destructions/damages caused by a virus attack
1. Delete or modify data, information and files on storage devices (disks) or memory during normal program execution, e.g., may attack the format of a disk making any program or data on it impossible to recover.
2. Systematically destroy all the data in the computer memory.
3. Might lock the keyboard.
4. Can change keystroke values or data from other I/O devices, e.g., change the effect of SHIFT key.
5. Delete characters displayed on a visual display.
6. Uses up computer memory/space, hence slowing down its performance or causing the system to crash.
7. Changes colour of the display.
8. Cause boot failure.
Sources of viruses.
a) Contact with contaminated systems
If a disk is used on a virus infected computer, it could become contaminated. If the same disk is used on another computer, then the virus will spread.
b) Use of pirated software
Pirated software may be contaminated by a virus code or it may have been amended to perform some destructive functions which may affect your computer.
c) Infected proprietary software
A virus could be introduced when the software is being developed in laboratories, and then copied onto disk containing the finished software product.
d) Fake games
Some virus programs behave like games software. Since many people like playing games on computers, the virus can spread very fast.
e) Updates of software distributed via networks
Viruses programs can be spread through software distributed via networks.
Symptoms of viruses in a computer system.
The following symptoms indicate the presence of a virus in your computer;
1) Boot failure.
2) Files and programs disappearing mysteriously.
3) Unfamiliar graphics or messages appearing on the screen, e.g., the virus might flash a harmless message such as "Merry Christmas" on the computer terminal.
4) Slow booting.
5) Gradual filing of the free space on the hard disk.
6) Corruption of files and programs.
7) Programs taking longer than usual to load.
8) Disk access time seeming too long for simple tasks.
9) Unusual error messages occurring more frequently.
10) Frequent read/write errors.
11) Disk access lights turning on for non-referenced devices.
12) Computer hangs anytime when running a program.
13) Less memory available than usual.
14) Size of executable files changing for no obvious reason.
Control measures against viruses.
1. Install up-to-date antivirus software on the computers.
2. Restrict the movement of foreign storage media, e.g., disk in the computer room. If they have to be used, they must be scanned for viruses.
3. Avoid opening mail attachments before scanning them for viruses.
4. Write-protect disks after using them.
5. Disable disk drives (ports), if there is no need to use disks in the course of normal operation.
6. Backup all software and data files at regular intervals.
7. Do not boot your computer from disks which you are not sure are free from viruses.
8. Avoid pirated software. If possible, use the software from the major software houses.
2). Unauthorized Access
Data and information is always under constant threat from people who may want to access it without permission.
Such persons will usually have a bad intention, either to commit fraud, steal the information and destroy or corrupt the data.
Unauthorized access may take the following forms;
a). Eavesdropping
This is tapping into communication channels to get information, e.g., Hackers mainly use eavesdropping to obtain credit card numbers.
b). Surveillance (monitoring)
This is where a person may monitor all computer activities done by another person or people.
The information gathered may be used for different purposes, e.g., for spreading propaganda or sabotage.
c). Industrial espionage
Industrial espionage involves spying on a competitor so as to get or steal information that can be used to finish the competitor or for commercial gain.
The main aim of espionage is to get ideas on how to counter by developing similar approach or sabotage.
d). An employee who is not supposed to see some sensitive data gets it, either by mistake or design.
e). Strangers who may stray into the computer room when nobody is using the computers.
f). Forced entry into the computer room through weak access points.
g). Network access in case the computers are networked and connected to the external world.
Control measures against unauthorized access
i). Enforce data & information access control policies on all employees to control access to data.
ii). Keep rooms with computers closed when nobody is using it.
iii). Reinforce weak access points, e.g., doors and windows with metallic grills and burglar alarms.
iv). Use file passwords to prevent any person from getting access to the electronic files.
v). Enforce network security measures, e.g., use of firewalls.
vi). Encrypt the data & information during transmission.
vii). Perform frequent Audit trails to identify threats to data and information.
3). Computer Errors and Accidental Access
Errors and accidental access to data and information may be as a result of:
1. Mistakes made by people, e.g., one may print sensitive reports and unsuspectingly give them to unauthorized persons.
2. People experimenting with features they are not familiar with. E.g., a person may innocently download a file without knowing that it is self-installing or it may be dangerous to the system.
Control measures against computer errors and accidents.
i). Restrict file access to the end-users and technical staff in the organization, i.e., deny access of certain files and computers to certain groups of end-users.
This is because; accidental access mistakes occur if the end-users have too much privilege that allows them to access or change sensitive files on the computer.
ii). Set up a comprehensive error-recovery strategy in the organization.
4). Theft
The threat of theft of data and information, hardware and software is real.
Unauthorized access may take the following forms;
a). Eavesdropping
This is tapping into communication channels to get information, e.g., Hackers mainly use eavesdropping to obtain credit card numbers.
b). Surveillance (monitoring)
This is where a person may monitor all computer activities done by another person or people.
The information gathered may be used for different purposes, e.g., for spreading propaganda or sabotage.
c). Industrial espionage
Industrial espionage involves spying on a competitor so as to get or steal information that can be used to finish the competitor or for commercial gain.
The main aim of espionage is to get ideas on how to counter by developing similar approach or sabotage.
d). An employee who is not supposed to see some sensitive data gets it, either by mistake or design.
e). Strangers who may stray into the computer room when nobody is using the computers.
f). Forced entry into the computer room through weak access points.
g). Network access in case the computers are networked and connected to the external world.
Control measures against unauthorized access
i). Enforce data & information access control policies on all employees to control access to data.
ii). Keep rooms with computers closed when nobody is using it.
iii). Reinforce weak access points, e.g., doors and windows with metallic grills and burglar alarms.
iv). Use file passwords to prevent any person from getting access to the electronic files.
v). Enforce network security measures, e.g., use of firewalls.
vi). Encrypt the data & information during transmission.
vii). Perform frequent Audit trails to identify threats to data and information.
3). Computer Errors and Accidental Access
Errors and accidental access to data and information may be as a result of:
1. Mistakes made by people, e.g., one may print sensitive reports and unsuspectingly give them to unauthorized persons.
2. People experimenting with features they are not familiar with. E.g., a person may innocently download a file without knowing that it is self-installing or it may be dangerous to the system.
Control measures against computer errors and accidents.
i). Restrict file access to the end-users and technical staff in the organization, i.e., deny access of certain files and computers to certain groups of end-users.
This is because; accidental access mistakes occur if the end-users have too much privilege that allows them to access or change sensitive files on the computer.
ii). Set up a comprehensive error-recovery strategy in the organization.
4). Theft
The threat of theft of data and information, hardware and software is real.
Some information is so valuable such that business competitors or some governments can decide to pay somebody a fortune so as to steal the information for them to use.
Control measures against theft of information, hardware, and software.
i). Create backups and store them in locations away from the main computing centre.
ii). Reinforce weak access points, e.g., the windows, doors, and roofing with metallic grills and strong padlocks.
iii). Put burglar proofs in the computer room.
iv). Employ guards to keep watch over data and information centres and backups.
Control measures against theft of information, hardware, and software.
i). Create backups and store them in locations away from the main computing centre.
ii). Reinforce weak access points, e.g., the windows, doors, and roofing with metallic grills and strong padlocks.
iii). Put burglar proofs in the computer room.
iv). Employ guards to keep watch over data and information centres and backups.
