Uncover what tools hackers use (2) _ Security-related

Second, the war on the love of Cats

★ War Dialing Machine

The principle of war dialers is simple, first of all, it uses ascending or random way to dial a series of phone numbers, once found hidden modem can dial into the system, and can crack easy to guess password. War dialer for PCs with no password and remote control software. This is often the case with the connection between a company's staff's computer and its corporate system. There are a lot of hackers who like to start from the staff's home computer, that's the truth. Many companies in order to prevent the black, spent a lot of time and money to build a firewall, that is necessarily foolproof, but the firewall only protects the front door of the network, some of the internal network has not logged in the modem but for hackers prepared a more convenient access to the back door, the war dialing function to use them into Obviously, this is one of the hacker's favorite tools.

☆ Defense of the War dialer method

The most effective way to prevent war dialer is to try to avoid connecting the PC with the modem and the main system. If you have to connect because of business needs, you should also register with the relevant department of the company and change it to the "only out" way of dialing. Enterprises must also have clear rules in this regard. Some people think that the PBX uses the digital line, nobody can install the modem privately, it is really wrong! Because the digital modem line is very cheap and easy to buy. In addition, the enterprise can also use the war dialer to find unregistered modem, for unnecessary should be all removed.

Third, the hacker's Swiss Army knife

★ Net Cat

The Net Cat (Netcat) is a tool for TCP/UDP protocol connections, first written by Mr. Hobbit for UNIX in 1995. By the year 1997, Mr. Weld Pond on the original basis, so that it can also be used on NT. Although the net cat's age is very old (note: in the IT industry, six months is a century), but the old and solid. Because of its powerful function, hackers call it the "Swiss Army Knife of hackers".

The main function of the net cat is to manage the system and detect the network error, but the water can carry the boat to overturn, the cat also has the claws of invading the network.

In the host mode, the net cat becomes the server, waits for the connection tcp/udp port, but in the client mode, the net cat may enable the user to connect any port, thus formed the rear door. In addition, the net cat can also scan the TCP/UDP port. Hackers often use it to obtain information about bank accounts, to change the amount of money and even transfer funds to other accounts, of course, can also steal other important information.

☆ The method of defending Netcat

Fully understand the programs running within the system to avoid unwanted ports passing through the firewall. For the outside can be close to the host is more should identify all the contents of the running program, otherwise it is easy to become a source of hacker intrusion. In addition, there should be an accurate log of the operation of the host.

Iv. concluding remarks

The above is the hacker commonly used intrusion tool and basic defense method. Of course, hackers will not only use one method, but as the case of mixed use: Usually hackers start the war dialer first to look for unprotected modem, and then take over the system and scan the network, backdoor on the host, log on to the server to intercept information, and then control the server, and then attack other sites.

The repeated occurrence of hacking, causing people to suspect the ability of system security personnel, many good people have been fired, in fact, it is not fair. From the point of view of work, the general work of engineering or management staff to "make something happen", and the first task of system security personnel is "to let something not happen," logically speaking, this is a more difficult task.