Online 312-38 Questions Video

The presence of packets with FIN, PUSH, and URG flags activated in network traffic, as observed through Wireshark, is indicative of a XMAS scan. This type of scan is used by attackers to identify open ports and services available on a networked computer. The peculiar combination of these TCP flags is not used in normal, everyday communications and is easily picked up by intrusion detection systems as anomalous. The XMAS scan derives its name from the fact that the packet lights up like a Christmas tree with several flags set, which is an unusual and conspicuous event in network traffic.

References: The characteristics of a XMAS scan and the use of these specific TCP flags are documented in network security literature and align with the Certified Network Defender (CND) course materials, which cover network scanning techniques and their identification123.

The Bell-LaPadula model is an example of a Mandatory Access Control (MAC) model. It is designed to maintain the confidentiality of information by enforcing access controls based on security classification levels. This model ensures that subjects (users) with a certain clearance level cannot read data at a higher classification level (no read-up) and cannot write data to a lower classification level (no write-down), thus preventing unauthorized access and information flow not permitted by the policy.

References: The Bell-LaPadula model is a foundational concept in computer security, particularly within the context of government and military applications where data classification and confidentiality are paramount12.

 The filter tcp.flags==0x003 is used to detect SYN/FIN attacks. This filter is designed to identify packets where both the SYN and FIN flags are set, which is an unusual combination and indicative of a potential SYN/FIN attack. In a typical TCP communication, a SYN flag is used to initiate a connection, and a FIN flag is used to gracefully close a connection. Therefore, seeing both flags set in a single packet suggests a malformed or malicious packet, which is characteristic of a SYN/FIN attack.

References: The use of the filter tcp.flags==0x003 for detecting SYN/FIN attacks is discussed in various cybersecurity resources and aligns with the knowledge required for the Certified Network Defender (CND) certification. This specific filter is mentioned in discussions about network security and intrusion detection techniques1.