CompTIA® A+ Practical Certification Exam Cram Notes

3. Computer Security

3.2 Common Prevention methods

Security Methods:

1. Anti-virus software, and Spyware software can be used to clear malicious programs from a computer. Also, note that you need to install up-to-date Service Packs, and patches.

2. It is recommended that the backup tape is stored at a location away from the building where the backup was taken. For most companies, backups contain important data and loosing backups may affect the continuity of one's business. If a backup is stored in the same building, it may get damaged in fire or any other natural calamities along with the computers. As a result, both the server, as well as back fail at the same time. Therefore, it is recommended to store the backup at a different location.

3. Mantraps are physical security devices or constructions designed to entrap a human. a man trap refers to a small space having two sets of interlocking doors, such that the first set of doors must close before the second set opens. They are also known as air locks in the security industry. Mantrap effectively prevents tailgating, in which an unauthorized person may enter a restricted premises simply following an authorized person.

4. Remote Wipe: Use this feature when a device is lost or stolen to erase all data on the device and reset the device. A remote wipe removes all device-based data like mail, calendar, and contacts from the device, but it may not delete data stored on the device's SD card.

5. Disabling any unused ports on a networking device will prevent any unauthorized persons from plugging in to the network and get sensitive data.

6. Authentication: CHAP uses 3-way handshaking. CHAP uses Challenge/ Response method which provides protection against the password capture while authenticating the user. One should use CHAP whenever it is possible. PAP uses 2-way handshaking. Passwords are sent in clear text across the link. Therefore, PAP is to be used only when it not possible to use CHAP.

7. Microsoft does not recommend manual removal of BHO virus or Trojans. To detect and remove this threat and other malicious software that may have been installed, run a full-system scan with an up-to-date antivirus product such as the Microsoft online scanner. Alternative, use any trusted third party scanner for identifying and removing the threat.

Given below are a few important precautions that you may need to take to prevent infections due to malware:

1. Install anti-virus/malware software. There are free as well as paid versions of software available. The Windows itself has a basic version of anti malware application by name Microsoft Security Essentials. You can enable the same at the least.

2. Keep operating system up to date. You can enable automatic updates so that you don't need to worry about manually updating your OS.

3. Update device drivers, and applications as necessary. Remove any unnecessary applications using add/remove programs.

4. Secure your network, don't keep any open ports and use secured cabinets wherever possible.

5. Do not open an email attachment from somebody that you do not know. Do not click on a link in an unsolicited email or messages.

6. Use difficult to guess passwords and disable "remember password" option in the browser bar.

7. Use encrypted Wi-Fi in home and office, preferably WPA2

8. Finally, back up your files. The best thing you can do to safe guard your work is to back up all your data. If you are involved in any serious work, the system is most likely to crash when its least expected. Therefore, it is important to backup all your data periodically.

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Anti-virus update files are traditionally called as "Definitions".

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MBR: Short for Master Boot Record, is stored on your hard drive but kept outside of Windows partitions and volumes. Crucially, the code in the MBR is run as your computer starts up (before Windows) which makes it an ideal place for a virus or rootkit to hide.

Even if you reinstall Windows or format your hard drive, a virus infecting the MBR will not be deleted. So, after you reinstall Windows, your computer first runs that same MBR virus code which then reinfects your new installation of Windows with viruses

You can remove MBR virus using a Recovery CD or Vista/7 Installation DVD by following the steps below:

1. Boot using a Recovery CD or Vista/7 Installation DVD to the Recovery Environment

2. At the System Recovery Options menu choose 'Command Prompt'

3. At the command prompt type in the command

4. bootrec /fixmbr

5. Press Enter to replace the MBR and then restart your computer.

Note that some anti-virus software are capable of detecting and removing MBR virus. However, one needs to be careful when using AV software for removing MBR virus.

Antispyware: Anti-spyware software detects spyware through rules-based methods or based on downloaded definition files that identify common spy ware programs. Anti-spy ware software can be used to find and remove spy ware that has already been installed on the user's computer, or it can act much like an anti-virus program by providing real-time protection and preventing spyware from being downloaded in the first place.

User authentication: Authentication begins when a user tries to access information. First, the user must prove his access rights and identity. When logging into a computer, users commonly enter usernames and passwords for authentication purposes. This login combination, which must be assigned to each user, authenticates access. However, this type of authentication can be circumvented by hackers. A better form of authentication, bio metrics, depends on the user's presence and biological makeup (i.e., retina or fingerprints). This technology makes it more difficult for hackers to break into computer systems.

Key fobs: A key fob is a small electronic security device with built-in authentication protocols or mechanisms to allow whoever possesses it to enter a secured network or location in order to access data or services. A key fob is designed to be small so that it can be carried around inconspicuously just like a key chain, hence the name key fob.

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