Knowledge about campus network security and virus protection

Source: Shenyang University of Technology

I. Overview of computer usage on Campus Network
There are a large number of computers connected to the campus network in our school. windows is widely used as the operating system, and various Internet Worms targeting windows systems are rampant, therefore, computer security protection and virus protection are very important.
In our daily work, many problems mentioned by users involve computer network security and virus protection. It is necessary to guide users to use computers securely and stably.
Ii. Several Questions Raised by common users
When using a computer, users often ask the following questions. The following is a brief answer.
1. Why does my computer suddenly slow down?
A: The computer may be infected with the worm and will not stop sending data packets. Run netstat-an at the command prompt to check whether the computer sends data packets to other machines on the LAN. It mainly checks whether the computer sends data packets to port 445 of other machines and whether the computer is infected with the worm, you can use the latest anti-virus software to scan and kill.
2. Why is my computer traffic suddenly increasing?
A: The computer may be infected with the worm or a trojan program, and someone else sets a proxy. You can run the "netstat-an" command to check whether your computer sends data packets to other computers in the LAN.
3. My computer has installed anti-virus software. Why do I still find viruses?
A: The user may accidentally open an attachment containing viruses in the email, or some software downloaded may contain virus programs, or the OS is attacked by the password worm because the password is not set or the administrator password is too simple, or the latest virus definition library is not updated in time.
We recommend that you update the virus definition library in a timely manner. For example, it is convenient to upgrade the virus definition of Norton Antivirus. You can also set Automatic Upgrade: Click Liveupdate in option, then select enable automatic Liveupdate in the displayed dialog box.
4. Why did my computer suddenly lose files and have an unknown account assigned?
A: This often happens in the Win2000 operating system. The computer may be attacked by the worm because the password is not set or the password is too simple, the virus will automatically add an administrator account in your system and implant a trojan program. Or some online users on the network use file: // xxx. xxx. xxx. if the Administrator account does not set a password or the password is too simple, the computer can be controlled immediately.
Solution: Set a complex password and change the Administrator account name.
5. I installed the OS patch (windows update) on my computer, installed the anti-virus software, and updated the virus definition file on time. Why was the trojan program planted?
A: There are several reasons, probably because the administrator password is too simple or the password is not set, it may be caused by the password worm attack; it may be because the attachment of the unknown email is opened; this may be due to the download of unknown software or programs.
The most thorough solution to these problems is to format the system disk and reinstall the operating system. Otherwise, the anti-virus software cannot completely remove viruses, or determine whether the system has a backdoor. The appendix below describes several common methods for the investigation of the virus infection.
Iii. Steps for installing the Computer Operating System
To reinstall a computer's software system, follow these steps:
1. Install Windows 98/2000/Xp with a boot disc that confirmed there was no virus. It is best to format the system disk using the ntfs file system.
2. The installation process is not described in detail, but note that if you are installing the Win2000 Advanced Server version, do not select the IIS component. If you need to use the IIS component, install the SDK after the system is fully installed.
3. Set a secure password for your administrator account during installation. Password setting requirements:
1) The password should be at least 8 characters long;
2) Chinese pinyin that does not contain words in the dictionary or surnames;
3) it can contain multiple types of characters at the same time, for example, writing letters (A, B, C ,.. z); lowercase letters (a, B, c .. z); Number (0, 1, 2 ,... 9); punctuation marks (@,#,!, $, % ,&...)
4. install anti-virus software immediately after the basic system is installed, and immediately upgrade the latest virus definition library. We recommend that you use the Norton Antivirus software.
5. Windows update: update the windows system patch on the windows site. The site will automatically scan the security patch and update options that your computer needs to install. This item takes a little longer, you only need to update windows recommended updates.
6. After all the recommended updates are updated, you can install the firewall software. If you do not install the software, it will not affect normal use. We recommend that you use Norton Security, you can select the system to automatically create firewall rules. In some cases, you may not be able to send or receive emails due to incorrect firewall rules. You can manually add a firewall rule. Because different versions of firewall software have different settings, it is not described here, you only need to set rules for the main program of the corresponding mail client software, that is, two-way access is allowed, most firewall software will create the corresponding rules according to the application software on the computer.
7. Reminder: if you are using a windows professional Edition, you can consider rename the administrator account name after installing the basic system, that is, rename the administrator account name under management tools> Account Management>, the change is called your familiar and favorite name. Because administrator is the default administrator Account of the system, the change helps prevent password worms from easily accessing the system.
Iv. Computer Security usage knowledge
After installing a complete system, pay attention to the following issues during daily use of the computer:
1. Regularly upgrade system security patches, regularly upgrade the virus definition library, and use automatic updates.
2. Do not open insecure email attachments, such as ". exe" files and ". chm" files.
3. Do not download or install small software or programs on the Internet.
4. regularly use anti-virus software to detect viruses in the system.
5. disable unnecessary services, such as file sharing and message services.
6. If your computer suddenly slows down or the traffic is abnormal, run the netstat-an command to check which ports are open and whether the computer sends packets to other addresses.
5. How to Avoid messenger interference
When surfing the Internet, users often encounter windows message dialog boxes. This is because the messager service is not turned off on the user's computer, and the method for disabling it is to enter the control panel, service, and select the Messager service option, after stopping, select disable. In this way, we can protect ourselves from spam.