Unveil what tools are used by hackers (2)

Ii. War on cat love

★War dialing Machine

The principle of war Dialers is simple. First, it dials a series of phone numbers in ascending order or randomly. Once hidden modem is found, it can dial into the system, and can crack easily guessed passwords. War dial-up machines are hundreds of thousands of computers that use remote control software without a password. The connection between the computer and the system of enterprise employees is usually in this form. Many hackers prefer to start from their home computers. Many companies have spent a lot of time and money building a firewall to protect the internet, and they think it is inevitable. However, the firewall only protects the front door of the network, some non-logged-on modem in the internal network has provided a more convenient backdoor for hackers, and the war dialing function uses them to access your network. Obviously, this is one of the favorite tools of hackers.

☆How to defend against war dialing machines

The most effective defense method for war dialing machines is to avoid the use of modem to connect personal computers to the main system. If the business needs to be connected, you should also register with the relevant departments of the company and change it to the "out-of-box" dialing method. Enterprises must also have clear regulations in this respect. Some people think that the PBX uses a digital line and no one can install the modem without authorization. This is a big mistake! Because digital modem lines are cheap and easy to buy. In addition, enterprises can also use war dial-up machines to find non-registered modem and remove all unnecessary ones.

Iii. Swiss Army Knife

★Webcat

Netcat is a tool used for TCP/UDP protocol connection. It was first written by Hobbit for UNIX in 1995.Program. By 1997, Mr. Weld pond had been carried forward on the basis of the original, so that it could also be used on NT. Although online cats are very old (Note: Half a year is a century in the IT industry), they are still mature. Because of its powerful functions, hackers call it the Swiss Army knife ".

The main function of the net cat is to manage systems and detect network errors. However, the water can carry the boat, and the CAT also has the claw of network intrusion.

In host mode, the Web cat becomes a server and waits for the TCP/UDP port to be connected. In client mode, the Web cat allows the user to connect to any port, thus forming a backdoor. The Internet cat can also scan TCP/UDP ports. Hackers often use it to obtain bank account information, change the amount or even transfer money to other accounts. Of course, they can also steal other important information.

☆Defense against Netcat

Fully understand the programs running in the system to avoid unnecessary ports passing through the firewall. For hosts that can be close to the outside world, the content of all running programs should be identified, otherwise it will easily become a channel for hacker intrusion. In addition, there should be precise logs on the running of the host.

Iv. Conclusion

These are common intrusion tools and basic defense methods used by hackers. Of course, hackers do not only use one method when they intrude into the system. Instead, they use a mix of methods based on the actual situation. Generally, hackers start the war dial to find unprotected modem, take over the system, and scan the network; open a backdoor on the host. log on to the server to intercept information and control the server. Then, attack other websites.

Hacker intrusions have repeatedly caused people to doubt the capabilities of system security personnel. Many outstanding talents have been fired. In fact, this is unfair. From the perspective of work purpose, the General connotation of the Work of engineering or management personnel is to "make some things happen ", the primary task of system security personnel is to "keep things from happening". Logically speaking, this is a more difficult task.