Forms of Network Attacks Gabriel Owens COSC 352

Forms of Network Attacks Gabriel Owens COSC 352 February 24, 2011

Roadmap n Definition n Different Forms of Attacks n Prevention n Conclusion n Questions? ?

Definition n What is a network attack? n Passive n Active

Different Types of Attack n n n n n Eavesdropping Data Modification Identity Spoofing (IP Address Spoofing) Password Based Attacks Denial of Service Attack Man-In-The-Middle-Attack Compromised-Key Attack Sniffer Attack Application-Layer Attack

Eavesdropping n n Majority of network communications occur in an unsecured or “cleartext” format. Allows attacker to “listen in” or read the network traffic. Known as Sniffing or Snooping Biggest security issue faced by network administrators in an enterprise.

Eavesdropping (cont. ) n Prevention n In order to prevent the eavesdropping of data traversed on your network, you must have strong encryption services based on cryptography.

Identity Spoofing n n n Computers are identified in an operating system or network by a valid IP Address. Possible for IP Address to be falsely assumed (identity spoofing). Special Programs to construct IP packets that appear to originate from valid addresses inside the corporate intranet. n After gaining access with a valid IP, attacker can modify, delete or reroute your data, As well as perform a number of other attacks.

Data Modification n Step One – Read Data n Step Two – Alter Data n n Modify data in the packet without the knowledge of the sender or receiver. Example: Purchase Requisitions, exchange of items, amounts and billing information

Password Based Attacks n n Access Rights to a computer or network resources are determined by who you are (username and password) If an attacker gains access to a valid user account he is able to do whatever that user can do n n n Obtain lists of valid user and computer names and network information. Modify server and network configurations, including access controls and routing tables. Modify, reroute, or delete your data.

Denial of Service Attack n n Prevents normal use of computer or network by valid users (Unlike Password Based Attack) After gaining access to the network n n Randomize the attention of your internal Information Systems staff so that they do not see the intrusion immediately, which allows the attacker to make more attacks during the diversion. Send invalid data to applications or network services, which causes abnormal termination or behavior of the applications or services. Flood a computer or the entire network with traffic until a shutdown occurs because of the overload. Block traffic, which results in a loss of access to network resources by authorized users.

Man-In-The-Middle Attack n n n Attacker is monitoring, capturing and controlling data sent between you and the person whom you are communicating with transparently At low levels of communication on the network layer, computers might not be able to determine with whom they are exchanging data. Attacker assumes your identity and attempts to gather as much information as possible, while the person you’re communicating with thinks it is you.

Compromised-Key Attack n n Definition: Key – A secret code or number that is needed to interpret secured information. Obtaining a Key: Difficult and Resource. Intensive, but possible. Attacker can use key to gain access on a secured communication without the knowledge of either party. Can also use key to attempt computation of additional keys, which would lead to access to other secure communications.

Sniffer Attack n n n Definition: Sniffer – An application or device that can read, monitor, and capture network data exchanges and read network packets. If packets aren’t encrypted, the Sniffer provides a full view of the data inside the packets. Using a Sniffer, an attacker is capable of: n n Analyzing your network and gain information to eventually cause your network to crash or to become corrupted. Read your communications.

Application-Layer Attack n n n Targets application servers by deliberately causing a fault in the server’s operating system or applications. Results in the attacker gaining the ability to bypass normal access controls. Capable of the same damages as a man -in-the-middle attack

Application-Layer (cont. ) n Once the attacker has gained access, he can do any of the following: n n n Read, add, delete, or modify your data or operating system. Introduce a virus program that uses your computers and software applications to copy viruses throughout your network. Introduce a Sniffer program to analyze your network and gain information that can eventually be used to crash or to corrupt your systems and network. Abnormally terminate your data applications or operating systems. Disable other security controls to enable future attacks.

Prevention n Always have some type of security plan in place. Have some sort of encryption service based on cryptography. Make sure all applications are up-todate in order to have as little vulnerabilities as possible.

Video n Denial of Service Attack - Example

Resources n n n "Common Types of Network Attacks. " Microsoft Tech. Net: Resources for IT Professionals. Web. 24 Feb. 2011. <http: //technet. microsoft. com/enus/library/cc 959354. aspx#main. Section>. "Strengthen Application Defenses to Prevent Network Attacks | Tech. Republic. " Tech. Republic - A Resource for IT Professionals. Web. 24 Feb. 2011. <http: //www. techrepublic. com/article/strengthen-applicationdefenses-to-prevent-network-attacks/5034342>. "Network Security Types of Attack Passive Attack Active. " Complete Computer Networking Notes Guides Tutorials. Web. 24 Feb. 2011. <http: //computernetworkingnotes. com/ccna_certifications/types _of_attack. htm>.

Questions n Questions? ?