ICS SCADA & Industrial Protocol Security 3

Question 1

What is 'defense in depth' as applied to ICS cybersecurity?

Accepted Answer

Applying multiple overlapping layers of security controls so that failure of one layer does not result in total compromise

Answer

Defense in depth applies multiple independent security layers — physical controls, network segmentation, authentication, monitoring — so that an attacker must defeat several barriers to cause harm.

Question 2

Which NIST publication serves as the primary guide for securing Industrial Control Systems?

Accepted Answer

NIST SP 800-82

Answer

NIST SP 800-82 'Guide to Industrial Control Systems (ICS) Security' provides guidance specific to SCADA, DCS, and PLC systems, including risk management and countermeasures tailored to OT environments.

Question 3

What is a 'data historian' in an ICS environment and why is it a security concern?

Accepted Answer

A time-series database server that stores process data and often bridges IT and OT zones, creating a potential attack pathway

Answer

A data historian (e.g., OSIsoft PI) stores time-series process data and is frequently connected to both the OT network (to collect data) and the IT network (to share data with business users), making it a potential pivot point for attackers.

Question 4

What is the purpose of a Demilitarized Zone (DMZ) placed between an IT network and an OT network?

Accepted Answer

To create an intermediate buffer zone that controls and mediates data exchange between the IT and OT environments

Answer

An IT/OT DMZ is an intermediate network segment that allows controlled data sharing (e.g., via a data historian or jump server) without establishing direct connections between the corporate network and the control system network.

Question 5

A false data injection attack against a SCADA system is best described as:

Accepted Answer

Manipulating sensor or process data transmitted to the SCADA system so operators receive false readings and make incorrect control decisions

Answer

A false data injection (FDI) attack involves an adversary intercepting and altering sensor readings or process values so the operator sees normal conditions while the actual process is in an abnormal or dangerous state.

(ICS) Industrial Control Systems Security Certification Practice Test

(ICS) Industrial Control Systems Security Certification Practice Test

ICS SCADA & Industrial Protocol Security 3