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Published byBeverly Kennedy Modified over 8 years ago
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Computer Network Attack “… actions taken through the use of computer networks to disrupt, deny, degrade, or destroy information resident in computers and computer networks, or the computers and networks themselves.” Not Computer Network Exploitation “…enabling operations and intelligence collection capabilities conducted through the use of computer networks to gather data from target or adversary automated information systems or networks.” Computer Network Attack2 Joint Publication 3-13
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Preventing access to information through denial, disruption, degradation, or destruction Does not require exploitation of the target system DDoS Driving a truck into a transformer Tripping over a wire in a datacenter Computer Network Attack3
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What most people consider “hacking” Enables further access into a target computer system. Gaining unauthorized privileges Also enables further intelligence gathering Provides access to user accounts Databases Password files Computer Network Attack6
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Intelligence collection Further assess target for other vulnerabilities Find information about target not otherwise available Corporate Espionage Gain access to trade secrets Profit Sell the information to the highest bidder Extortion Botnets Hacktivism Ideological view of something (Anonymous, LulzSec, etc) Social Status Be that “ l33t h4X0r” ( geek translation: elite hacker) Other Destruction of information systems Computer Network Attack7
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Computer Network Attack11
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Simply gaining access to a host is not necessarily enough for an attacker to accomplish his goal - the attacker may have to escalate privileges to those of another user. Attackers want to access a file that belongs to another user (timvic) and which has permissions set so that only that user is allowed to access it. Other examples of access an attacker might want to take that require higher privileges are killing processes they don't own or opening network connections on "low-numbered" ports, like port 80, that have special meanings. Computer Network Attack13
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Password guessing works if users on the target system are allowed to use simple passwords Remember, the longer and more complex the password, the more difficult it is to break. 4 characters (upper/lower case) 52 4 = ~ 7 million 7 characters (A-Z, a-z, 0-9) 62 7 = ~ 3.5 trillion Brute forcing passwords takes a long time Still works! Users choose inherently bad passwords all the time passw0rd12345lovesecret password1passgod Computer Network Attack14
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Password guessing also works against predictable passwords Pet’s name Significant other Phone number Password reuse Default passwords (as we saw in lab) can really cause problems if not changed. Routers, smart devices, even the iPhone come with default passwords set Early iPhones could be “rooted” because of a weak default password (alpine) Voicemail systems Computer Network Attack15
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Code Injection is another means to exploit a target machine. Can be local or remotely exploited Involves sending specially crafted data to a computer system to cause it to misbehave. Buffer Overflows SQL Injections Trojan Horses Computer Network Attack16
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Take advantage of vulnerabilities in code Allow the intruder to send arbitrary code of his or her choosing to a machine for execution. Used to gain access to a machine for DoS Commonly used for privilege escalation as well Computer Network Attack17 http://httpd.apache.org/security/vulnerabilities_20.html http://rona.cs.usna.edu/~wcbrown/si110/lec/l34/bodemo.html
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Take advantage of structured queries to a database Data entered in a format that causes the application to perform some task it is not designed for May give access to customer data, passwords, credit card numbers, etc Can also be used to write files to the hard drive Can I rewrite an ACL to allow access for unauthorized personnel? Very common web application vulnerability Computer Network Attack18
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Malicious code included in an innocuous program. Embedded either within the application directly, or by binding it to a pre-compiled executable. Can be used to take control of hosts and allow the attacker to do anything a user sitting in front of the machine could do. Computer Network Attack19
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Once the intruder has a foothold in the system or has enough information about it, they can choose one of two options Attack Erasing the hard drive Modifying the information contained on the drive. DoS, DDoS Further exploitation Escalate privilege to gain better foothold Steal passwords Essentially, start from the beginning if necessary to gain more access. Computer Network Attack20
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