Four tips to learn Security

Compared with LAN users, General dial-up Internet users are often at a disadvantage in preventing hacker intrusion. A stolen account can be used by hackers as a springboard to engage in network damage activities. The following methods help dial-up users to prevent hacker intrusion.

I. Frequent password changes

It is a simple and effective method. Many hackers use brute force to crack passwords. password cracking programs such as John can be downloaded free of charge from the Internet, as long as a dictionary is large enough to run on a machine that is fast enough, you can obtain the required account and password. The following four principles can improve the password's anti-cracking capability.

1. ask others to change their passwords immediately after installation

This is an easy-to-ignore detail. For the first time many users don't know how to dial up the Internet, they ask others to teach them. In this way, they often tell the user name and password to this person, this person will be able to steal the service in the future.

2. Use the terminal window function after dialing
　　
Select a connection, right-click, and select "properties/General/configuration/options/terminal window after dialing". Then, when dialing, do not enter the user name and password on the dial-up interface (do not select "Save Password ). After the dial-up terminal window appears, enter the corresponding user name and password. This prevents the user name and password from being recorded in the password file on the hard disk. At the same time, it can be avoided by some hacker programs.

3. Delete the. pwl file

In the Windows directory. pwl is a password file with the suffix. In the Win95 operating system, the password is stored with a security vulnerability. Hackers can easily obtain and save the password in the corresponding program. the password in the pwl file. This vulnerability has been fixed in Win97. Therefore, you should install an operating system later than Win97 and delete these. pwl files frequently.

4. Do not install the key logging program.

Doskey.exe is widely known. It can speed up the input of commands by restoring previous commands. in Windows, there are also many similar programs, such as keylog, it not only records the user's key actions, but also records what happened on the screen in the form of snapshots; in addition, some programs can record the keys and letters to a specific file in the root directory, and this file can be viewed in a text editor, so that hackers can see it clearly in the root directory.

Ii. Dealing with Trojan horses

A Trojan program is often defined as a program that actually executes another task when executing a task, this kind of program can be described in terms of "Crossing the sea in the sky" or "Wolf in sheepskin. A typical example is that hackers forge a logon interface. When a user enters the user name and password on this interface, the program transfers them to a hidden file and then prompts an error, the user is required to enter it again, and then the program calls the real logon interface to log on to the user. As a result, the hacker obtains a file with a user name and password under almost imperceptible conditions.

There are several ways to deal with Trojan Horse programs.

1. Read readme.txt and install it again

Many people download some Trojan Horse software packages for research purposes, and rush to execute the programs before figuring out the specific functions of several programs in the software package, in this way, the server program is mistakenly executed, and the user's computer becomes a victim of the Trojan horse. Read the instructions in readme.txt.

2. Use anti-virus software

Anti-Virus Software in China now has the ability to clear some Trojans, which can be checked and cleared occasionally offline. In addition, some anti-virus software also provides the network real-time monitoring function, which can provide an alarm or cause execution failure when hackers execute files on users' machines from the remote end.

3. Disconnect now

Although there are many reasons for the sudden slowdown in Internet access, there is reason to suspect that this is caused by a Trojan horse. When an intrusion uses a trojan client to access your machine, it will seize the bandwidth with your normal access, double-click the connection icon in the lower right corner of the taskbar, and carefully observe "sent bytes ", if the number is changed to l ~ 3 kbps, you can almost confirm someone is downloading your hard disk file; users familiar with TCP/IP ports, press "netstat-a" in "MS-DOS mode" to observe all current communication processes connected to your machine when someone is using an uncommon port (typically greater than 1024) when communicating with you, this port is probably the communication port of the Trojan horse. When these suspicious signs are found, the connection is immediately disconnected and the hard disk is carefully checked.

4. Observe the Directory

Always observe the files in the C:, C: Windows, C: WindowsLsystem directories. In C: Windows, if an executable program with a file name and no icon is available, delete the programs and Use anti-virus software to clean them up.

3. Do not share Hard Disks

For Windows 98 users who use the remote dial-up access LAN function, use hard disk sharing and file sharing with caution, because sharing means allowing others to download files.

4. Carefully store Word and Excel files

By default, Word and Excel files are stored in the "My Documents" folder under the root directory. After a Trojan horse turns a user's hard disk into a shared hard disk, attackers can see at a glance what the user is doing from the file name in this directory. For security, you should change the working path to another directory, and the deeper the level, the better.