Remote Control of Linux using VNC (1)

In movies, we often see that a hacker remotely controls a computer and can perform any operations on it, such as opening the camera of the other party. Is this difficult? Actually not. As long as you have the account and password of the other operating system, you can remotely control the Linux operating system. Today, I will introduce how to remotely control the Linux operating system through VNC.

I. features and applications of VNC.

Remote control is a technology in which one computer controls another computer. The controlled computer is called the controlled computer, and the computer that controls others' computers is called the control computer. When the control end is controlled by the control end, the control end can execute any application of the control end and use any system resources of the control end, just as if the user is sitting in front of the control end. The premise is that the account used by the master has the corresponding permissions. For example, the controller can easily open the camera on the passive side. Imagine what a terrible thing a user might not shut down his computer during lunch break if the camera is opened silently on the master side. However, when remote control technology was developed, its intention was good. As long as it is used to help the system administrator achieve remote management and remote assistance. It was later exploited by hackers to conduct some illegal activities.

In the open-source field, remote control technology is represented by VNC. VNC (Virtual Network Computer) is a set of software developed by AT&T lab that can control remote computers. This software is open-source. That is to say, anyone can obtain and use this software for free. The VNC software can be divided into two parts: VNC Server and VNC viewer. The former is installed on the controlled terminal, and the latter is installed on the master terminal. VNC software is not only open-source, but also cross-platform. That is to say, it can be used not only in Linux but also in Windows. For this reason, many system administrators may use Microsoft's operating system and prefer to use this VNC as a tool to remotely manage Linux servers or clients.

In addition, I have also used a commercial remote control software, which is a pcAnywhere tool developed by Symantec. This tool is relatively more powerful than VNC software. Both security and controllability cannot be compared. However, this software is commercial, and enterprises must pay for it. He does not support Linux, so far he can only use it on Windows. This greatly limits the scope of use. I will take the VNC software as an example to talk about how to remotely control the Linux operating system.

2. Start the VNC server on the Linux operating system.

The basic principle of Remote Control Using VNC software is that the master node initiates a connection request using the VNC client and establishes remote control after the control end agrees. In this case, the master can remotely control the control end. To remotely control the Linux operating system using the VNC software, you must first start the VNC server software on the Linux operating system. Otherwise, you cannot establish a VNC connection. However, in most Linux operating systems, such as Red Hat Linux systems, VNC servers are usually installed by default. However, it is usually disabled for security reasons. If the system administrator wants to use VNC for remote control, the system administrator needs to start the VNC server on the Linux operating system.

In the Linux operating system command line, the system administrator can enter the vncserver command to start the VNC server. During the startup process, the operating system prompts the system administrator to enter the VNC connection password for security reasons. It is better for the system administrator to enter a complicated password here, such as a combination of English characters and numbers, to increase the difficulty of supplier deciphering. After a VNC connection is established, the master can operate on the control end as you would on your computer. Therefore, this password will be the final barrier to ensure its security.

After the password is configured, the Linux operating system returns the VNC connection address. As shown above, the system administrator can use mail.dfg.cn to remotely manipulate the Linux operating system. After entering this network address on the VNC client, you can connect to the VNC server. If you need to change the VNC connection password later, you need to use vncpasswd to change it. Note that it is not passwd. This is different from the command for changing the user password. Generally, as long as the network address is displayed normally, the VNC service starts normally.