ICS-SCADA Questions and Answers

The maximum transmission unit (MTU) for Ethernet, which is the largest size of an Ethernet packet or frame that can be sent over the network, is typically 1500 bytes. This size does not include the Ethernet frame's preamble and start frame delimiter but does include all other headers and the payload. Ethernet's MTU of 1500 bytes is a standard for most Ethernet networks, especially those conforming to the IEEE 802.3 standard.References:

IEEE 802.3-2012, "Standard for Ethernet".

To determine the correct Security Association (SA) in the context of IPsec, several elements are required:

SPI (Security Parameter Index): Uniquely identifies the SA.

Partner IP address: The address of the endpoint with which the SA is established.

Protocol: Specifies the type of security protocol used (e.g., AH or ESP). All these components collectively define and identify a specific SA for secure communication between parties.References:

RFC 4301, "Security Architecture for the Internet Protocol".

A "watering hole" attack is a security exploit in which the attacker seeks to compromise a specific group of end users by infecting websites that members of the group are known to visit.

The goal is to infect a website that members of a targeted community frequently use with malware. Once a user visits the compromised website, malware can be delivered to the user’s system, exploiting vulnerabilities on their device.

This attack vector is used in scenarios where attackers want to breach secure environments indirectly by targeting less secure points in a network's ecosystem, such as third-party software used within the organization.

References

"Watering Hole Attacks: Detect, Disrupt, and Prevent," by Kaspersky Lab.

"Emerging Threats in Cybersecurity: Understanding Watering Hole Attacks," published in the Journal of Network Security.

TCP (Transmission Control Protocol) is a connection-oriented protocol used in the majority of internet communications.

Connection-oriented protocols like TCP require a connection to be established between the communicating devices before data is transmitted. This ensures reliable and ordered delivery of data.

TCP manages this by establishing a handshake mechanism (TCP three-way handshake) to set up the connection prior to transmitting data and properly terminating the connection once the communication session has completed.

References

"TCP/IP Illustrated, Volume 1: The Protocols" by W. Richard Stevens.

Postel, J., "Transmission Control Protocol," RFC 793.

Ingress filtering is a method used in network security to ensure that incoming packets are allowed or blocked based on a set of security rules.

This type of filtering is often implemented at the boundaries of networks to prevent unwanted or harmful traffic from entering a more secure internal network.

The term "ingress" refers to traffic that is entering a network boundary, whereas "egress" refers to traffic exiting a network.

References

Cisco Networking Academy Program: Network Security.

"Understanding Ingress and Egress Filtering," Network Security Guidelines, TechNet.

A network switch typically operates at Layer 2 of the OSI model, which is the Data Link layer. This layer is responsible for node-to-node data transfer—a function that involves handling data frames between physical devices on the same network or link. The switch uses MAC addresses to forward data to the appropriate destination within the network.References:

Andrew S. Tanenbaum, "Computer Networks".

Modbus TCP is a variant of the Modbus family of simple, networked protocols aimed at industrial automation applications. Unlike the original Modbus protocol, which runs over serial links, Modbus TCP runs over TCP/IP networks.

Port 502 is the standard TCP port used for Modbus TCP communications. This port is designated for Modbus messages encapsulated in a TCP/IP wrapper, facilitating communication between Modbus devices and management systems over an IP network.

Knowing the correct port number is crucial for network configuration, security settings, and troubleshooting communications within a Modbus-enabled ICS/SCADA environment.

References

Modbus Organization, "MODBUS Application Protocol Specification V1.1b3".

"Modbus TCP/IP – A Comprehensive Network protocol," by Schneider Electric.

A data diode is known as a prebuilt directional gateway that is unidirectional, designed specifically to allow data to travel in only one direction, ensuring secure one-way communication. This feature makes data diodes ideal for environments where it iscritical to prevent any possibility of data leakage or unauthorized access from an external network back to a secure network. Data diodes are commonly used in military and industrial applications, including ICS/SCADA systems, to protect sensitive information.References:

U.S. Department of Energy, "Cybersecurity for SCADA Systems".

ICMP (Internet Control Message Protocol) is used in network devices, like routers, to send error messages and operational information indicating success or failure when communicating with another IP address.

An ICMP type 8 packet specifically is an "Echo Request." It is used primarily by the ping command to test the connectivity between two nodes.

When a device sends an ICMP Echo Request, it expects to receive an ICMP Echo Reply (type 0) from the target node. This mechanism helps in diagnosing the state and reachability of a network on the Internet or within a private network.

References

RFC 792 Internet Control Message Protocol: https://tools.ietf.org/html/rfc792

Internet Assigned Numbers Authority (IANA) ICMP Parameters:

In ICS/SCADA systems, the typical priority hierarchy of the IT Security Model components places Availability and Integrity above Confidentiality. This prioritization is due to the critical nature of operational continuity and data accuracy in industrial control systems, where system downtime or incorrect data can lead to significantoperational disruptions or safety issues. Confidentiality, while important, is often considered of lesser priority compared to ensuring systems are operational (Availability) and data is accurate (Integrity).References:

National Institute of Standards and Technology (NIST), "Guide to Industrial Control Systems (ICS) Security".

The Modbus protocol was developed by Modicon, now a brand of Schneider Electric.

It was originally designed in 1979 for use with its programmable logic controllers (PLCs) in industrial applications.

Modbus is a serial communications protocol that has become a de facto standard communication protocol and is now commonly used to connect industrial electronic devices. The main reasons for its use are its simplicity and the fact that it is open-source, which allows manufacturers to build their own implementations of the standard.

References

"Modbus Protocol Reference Guide," Modicon, Inc., 1979.

"A Guide to the Modbus Protocol," Schneider Electric.

Eavesdropping and interception primarily attack the confidentiality component of the IT Security Model. Confidentiality is concerned with protecting information from beingaccessed by unauthorized parties. Eavesdropping involves listening to private communication or capturing data as it is transmitted over a network, thereby breaching the confidentiality of the information.References:

William Stallings, "Cryptography and Network Security: Principles and Practice".

In the context of monitoring and alerts within cybersecurity, the classification of alerts includes true positives, false positives, true negatives, and false negatives.

A false negative is considered the most dangerous type of alert because it occurs when an actual security threat is present but the monitoring system fails to detect and alert it. This allows malicious activities to occur undetected, potentially leading to significant damage or data loss.

The risk with false negatives is that they provide a false sense of security, assuming that systems are secure while in reality, they are compromised.

References

"Security and Network Monitoring Basics," Cisco Systems.

"Understanding Alert Classifications in Cybersecurity," Journal of Information Security.

The term "Dropper" in cybersecurity refers to a small piece of software used in malware deployment that is designed to install or "drop" malware (like viruses, ransomware, spyware) onto the target system.

The Dropper itself is not typically malicious in behavior; however, it is used as a vehicle to install malware that will perform malicious activities without detection.

During the infection process, the Dropper is usually the first executable that runs on a system. It then unpacks or downloads additional malicious components onto the system.

References

Common Malware Enumeration (CME): http://cme.mitre.org

Microsoft Malware Protection Center:https://www.microsoft.com/en-us/wdsi

The PSH (Push) flag in the TCP header instructs the receiving host to push the data to the receiving application immediately without waiting for the buffer to fill. This is used to ensure that data is not delayed, thus improving the efficiency of communication where real-time data processing is required. It effectively tells the system that the data in the packet should be considered urgent.References:

Douglas E. Comer, "Internetworking with TCP/IP Vol.1: Principles, Protocols, and Architecture".

LACNIC (Latin American and Caribbean Network Information Centre) is the regional Internet registry for Latin America and parts of the Caribbean. It manages the allocation and registration of Internet number resources (such as IP addresses and AS numbers) within this region and maintains the registry of domain owners in South America.References:

LACNIC official website, "About LACNIC".

Industrial Control Systems (ICS) and SCADA networks typically operate in environments where the available bandwidth is limited. They are often characterized by:

Low processing threshold: ICS/SCADA devices generally have limited processing capabilities due to their specialized and often legacy nature.

Legacy systems: Many ICS/SCADA systems include older technology that might not support newer security protocols or high-speed data transfer.

Weak network stack: These systems may have incomplete or less robust network stacks that can be susceptible to specific types of network attacks.

High bandwidth networks are not typical of ICS/SCADA environments, as these systems do not usually require or support high-speed data transmission due to their operational requirements and the older technology often used in such environments.

References

"Navigating the Challenges of Industrial Control Systems," by ISA-99 Industrial Automation and Control Systems Security.

"Cybersecurity for Industrial Control Systems," by the Department of Homeland Security.