Pass the ECCouncil Certified Ethical Hacker EC0-350 Questions and answers with CertsForce

As little information as possible should be given about a failed login attempt. Invalid username or password is not desirable.

To a server that requires an exchange of a sequence of messages. The clientsystem begins by sending a SYN message to the server. The server thenacknowledges the SYN message by sending a SYN-ACK message to the client. Theclient then finishes establishing the connection by responding with an ACKmessage and then data can be exchanged. At the point where the server systemhas sent an acknowledgment (SYN-ACK) back to client but has not yet receivedthe ACK message, there is a half-open connection. A data structuredescribing all pending connections is in memory of the server that can bemade to overflow by intentionally creating too many partially openconnections. Another common attack is the SYN flood, in which a target machine isflooded with TCP connection requests. The source addresses and source TCP ports of the connection request packets are randomized; the purpose is to force the target host to maintain state information for many connections that will never be completed. SYN flood attacks are usually noticed because the target host (frequently an HTTP or SMTP server) becomes extremely slow, crashes, or hangs. It's also possible for the traffic returned from the target host to cause trouble on routers; because this return traffic goes to the randomized source addresses of the original packets, it lacks the locality properties of "real" IP traffic, and may overflow route caches. On Cisco routers, this problem often manifests itself in the router running out of memory.

Actually the objective of the rootkit is more to hide the fact that a system has been compromised and the normal way to do this is by exchanging, for example, ls to a version that doesn’t show the files and process implanted by the attacker.

Explanations:

Microsoft is not the exploit, but if Microsoft documents how the vulnerability can be used to gain unprivileged access, they are creating the exploit. If they just say that there is a hole in the product, then it is only a vulnerability. The security "hole" in the product is called the "vulnerability". It is documented in a way that shows how to use the vulnerability to gain unprivileged access, and it then becomes an "exploit". In the example given, Windows 2003 Server is the TOE (Target of Evaluation). A TOE is an IT System, product or component that requires security evaluation or is being identified. The hacker that would use this vulnerability is exploiting it, but the hacker is not the exploit. The documented method of how to use the vulnerability to gain unprivileged access is the correct answer.

A man-in-the-middle attack (MITM) is an attack in which an attacker is able to read, insert and modify at will, messages between two parties without either party knowing that the link between them has been compromised.

A man-in-the-middle attack (MITM) is an attack in which an attacker is able to read, insert and modify at will, messages between two parties without either party knowing that the link between them has been compromised.

NULL sessions take advantage of “features” in the SMB (Server Message Block) protocol that exist primarily for trust relationships. You can establish a NULL session with a Windows host by logging on with a NULL user name and password. Primarily the following ports are vulnerable if they are accessible:

POP is used to receive e-mail.

SMTP is used to send e-mail.

Brute force cracking is a time consuming process where you try every possible combination of letters, numbers, and characters until you discover a match.

He is actually trying to get the file har.txt but this file contains a copy of the SAM file.

-l forces netcat to listen for incoming connections.

-u tells netcat to use UDP instead of TCP

-p 5555 tells netcat to use port 5555

< /etc/passwd tells netcat to grab the /etc/passwd file when connected to.

The teardrop attack uses overlapping packet fragments to confuse a target system and cause the system to reboot or crash.

Canonicalization (abbreviated c14n) is the process of converting data that has more than one possible representation into a "standard" canonical representation. This can be done to compare different representations for equivalence, to count the number of distinct data structures (e.g., in combinatorics), to improve the efficiency of various algorithms by eliminating repeated calculations, or to make it possible to impose a meaningful sorting order.

In computing, GINA refers to the graphical identification and authentication library, a component of some Microsoft Windows operating systems that provides secure authentication and interactive logon services.

Explanations:

SNMPUtil is a SNMP enumeration utility that is a part of the Windows 2000 resource kit. With SNMPUtil, you can retrieve all sort of valuable information through SNMP. SNScan is a SNMP network scanner by Foundstone. It does SNMP scanning to find open SNMP ports. Solarwinds IP Network Browser is a SNMP enumeration tool with a graphical tree-view of the remote machine's SNMP data.

The zone transfer is the method a secondary DNS server uses to update its information from the primary DNS server. DNS servers within a domain are organized using a master-slave method where the slaves get updated DNS information from the master DNS. One should configure the master DNS server to allow zone transfers only from secondary (slave) DNS servers but this is often not implemented. By connecting to a specific DNS server and successfully issuing the ls –d domain-name > file-name you have initiated a zone transfer.

The easiest programs to trojan and the smartest ones to trojan are ones commonly run by administrators and users, in this case netstat, ps, and top, for a complete list of commonly trojaned and rootkited software please reference this URL: http://www.usenix.org/publications/login/1999-9/features/rootkits.html

MD5 was developed by Professor Ronald L. Rivest of MIT. What it does, to quote the executive summary of rfc1321, is:

[The MD5 algorithm] takes as input a message of arbitrary length and produces as output a 128-bit "fingerprint" or "message digest" of the input. It is conjectured that it is computationally infeasible to produce two messages having the same message digest, or to produce any message having a given prespecified target message digest. The MD5 algorithm is intended for digital signature applications, where a large file must be "compressed" in a secure manner before being encrypted with a private (secret) key under a public-key cryptosystem such as RSA.

In essence, MD5 is a way to verify data integrity, and is much more reliable than checksum and many other commonly used methods.

The “Get /msadc/……/……/……/winnt/system32/cmd.exe?” shows that a Unicode Directory Traversal Attack has been performed.