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Showing posts with label Wireless security. Show all posts
Showing posts with label Wireless security. Show all posts

Tuesday, November 19, 2013

What are the different types of attacks that network face?

With a lack of security measures and checks in the right place, we put our data to risk of various types of attacks, with many of these attacks of the level that there could be significant data loss, as well as the data could be stolen (and when this data is something sensitive such as credit card numbers or social security numbers, then it is a very serious matter).
Attacks are of two types namely active attacks and passive attacks. The active attacks involve altering the information with an intention of destroying or corrupting the network and the data. If you do not have a security plan in place your network and data are vulnerable to these types of attacks. In this article we discuss about few of such attacks:
- Eavesdropping: Generally most of the network communications occur in a format that is very unsecure (i.e., clear text). This gives a chance to the attacker to gain access to all the available data paths in that network for interpreting or listening to the traffic. Eavesdropping on someone’s communication is referred to as snooping or sniffing. The eavesdropper gets a great chance for monitoring the whole network which has become a great cause of concern for the administrator of an enterprise. There are services that are based on cryptography and can prevent this type of attack. With a lack of strong encryption data can be read or traversed by the eavesdropper.
- Data modification: After the data has been read by the attacker or eavesdropper, altering this data is his/ her next step. Without coming to the knowledge of the receiver and the sender, the data in the packet can be modified by the attacker. Even if confidentiality is not required in all the communications, it is a must that any of the messages should not get modified in the transition.
- IP address spoofing (identity spoofing): The computer’s IP address is used by most of the operating systems and the network for identifying whether an entry is valid or not. In some cases, a false assumption of the IP address is possible. This is called identity spoofing. Some special programs might be used by the attacker for constructing the IP packets that might seem to come from the systems that are inside the intranet of the corporate. After the attacker gains the access to a network having a valid IP address, he/ she might reroute, delete or modify the data.
- Attacks based up on passwords: Password based access control is a common denominator of many network security plans and operating systems. By this we mean that your user ID and password determine your access rights. However, it is possible that protection to this identity information is not provided by older applications as they might be validated when passed through the network. This might give a chance to the eavesdropper who poses as an authorized user for gaining access to the data. Whenever a valid user account is found by the attacker, he/ she gets the exact rights which are possessed by the real user. Now suppose if the user is admin of the network, then attacker gets the same rights as the admin and can create accounts for subsequent use. After gaining access to an account, the attacker can get lists of the authorized users and network info. He can make changes in the configurations, routing tables and access controls of the networks and servers.
- Denial – of – service attack: This attack prevents a valid user from using the network or the computer. By means of this attack the attention of the staff can be diverted from the internal information systems so that they don’t get to know about the intrusion. In the meantime attacker can make more attacks. Invalid data can be sent to the network services or applications. He can even overload the whole network so that it shut down.


Friday, November 8, 2013

Quick detail of some network security tools

Every web application and site can face pretty intense security threats such as cross site scripting, account hacking and so on, with new ones emerging on a regular basis. The load on the security providing vendors is increasing day by day for building products that offer more security while being able to respond quickly to new threats. As we develop new security measures and tools, the attackers also develop new methods for hampering the security. Some of the network security tools have to be paid for while others are open source tools (that can help you a lot and are effective). To a great extent these tools perform the task exactly as you like it but sometimes their settings have to be customized as per the security needs of the structure of the network. Some examples of the open source tools are Ettercap, nikto, Nessus etc. discussed below:
1. Wireshark: This is a multi – platform network protocol analyzer which is available as an open source tool. Using it the data can be examined from a file captured on the disk or from a live network. The data can be browsed and the exact details can be obtained. It comes with very useful features such as filter language with a rich display, and a view of the reconstructed TCP session stream. It also comes with support for a number of media types and protocols.
2. Metasploit: This one is also an open source tool but with advanced features for development, and testing of the exploit code. Metaspoilt framework is now being used as an exploitation research outlet because of the extensible models which is used for integrating the encoders, exploits, payloads and no – op generators. This tool makes it easy for you to write your own exploits. An official java based GUI is now included with the framework.
3. Nessus: This tool provides excellent capabilities for scanning the potential vulnerabilities of the unix systems. Initially it was an open source tool till 2008. It now comes for a good price and is still ahead of many of its competitor. A licensed version is also available for use in the home network. The tool boasts of having a whopping 46000 plugins. Some features are embedded scripting language that allows you to write your own plugins, client – server architecture having a web – based interface, local as well as remote security checks.
4. Aircrack: This is a tool suite developed especially for the 802.11 a/b/g WEP and WPA cracking. This tool makes use of the well-known cracking algorithms for recovering the wireless keys. This it does only after the encrypted packets have been gathered. Some of the tools in this suite are airodump, aircrack, airdecap, aireplay and so on.
5. Snort: This tool has proved very good in detecting and preventing network intrusions. This is a very effective tool for analysis of traffic and packet logging on the networks. The tool has capability of detecting 1000s of worms by means of content searching, protocol analysis, pre – processors and so on. It is also capable of port scanning, vulnerability exploit attempts etc. it is based up on a rule – based language which is quite flexibility.
6. Cain and Abel: This is a tool that has been developed for handling the windows – only password recovery and for handling various other tasks as well. It is capable of performing the following functions:
- Recovery of the password by sniffing the network.
- Cracking the passwords that are encrypted by means dictionary.
- Cryptanalysis and brute – force attacks.
- Recording the VoIP conversations
- Revealing the password boxes.
- Decoding the scrambled passwords.
- Analyzation of the routing protocols.
The tool comes with proper documentation.

There are others as well, this is a quick summary of some of them. If you use others or have some feedback, do let me know via comments.


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