The internet has become a primary conduit for cyber-attack activities, with hackers channeling threats through social-engineering attacks and even using legitimate websites, meaning that more people are at greater risk than ever before. Financial fraud, phishing, malware, man-in-the-middle, man-in-the-browser and man-in-the-mobile attacks continually result in huge losses for consumers and companies alike. This has prompted the cyber security technology market to flourish and make significant strides in revenue. However, it’s important not to lose sight of the fact that the end goal is to protect as many end users as possible.
The criminals target end users to make money, and as cyber security providers, we need to protect consumers and companies from these targeted attacks. To successfully thwart attacks, a multi-layered approach to security is best. A multi-layered approach can be tailored to different levels of security. Not every asset needs to be completely secure; instead, only the most business critical assets, such as proprietary and confidential information, can be protected by the most restricted settings. If one system fails, there are other systems functioning. By using multiple systems to mitigate damage, the organization can ensure that even if one (or multiple) systems fail, the system itself is still protected.
There are many niche solutions – and threats. Organizations today often need to maintain multiple cyber security applications, such as antivirus programs, anti-spyware programs, and anti-malware programs.
Typical multi-layer approach involves five areas: physical, network, computer, application and device.
Physical Security – It seems obvious that physical security would be an important layer in a defense-in-depth strategy, but don’t take it for granted. Guards, gates, locks, port block-outs, and key cards all help keep people away from systems that shouldn’t touch or alter. In addition, the lines between the physical security systems and information systems are blurring as physical access can be tied to information access.
Network Security – An essential part of a plant’s information fabric, network security should be equipped with firewalls, intrusion detection and prevention systems (IDS/IPS), and general networking equipment such as switches and routers configured with their security features enabled. Zones establish domains of trust for security access and smaller local area networks (LANs) to shape and manage network traffic. A demilitarized zone between the industrial plant floor or space and the IT and corporate offices allows data and services to be shared securely.
Computer Hardening – Well known (and published) software vulnerabilities are the number one way that intruders gain access to automation systems. Examples of Computer Hardening include the use of:
- Antivirus software
- Application white-listing
- Host intrusion-detection systems (HIDS) and other endpoint security solutions
- Removal of unused applications, protocols and services
- Closing unnecessary ports
- Computers on the plant floor (like the HMI or industrial computer) are susceptible to malware cyber risks including viruses and Trojans. Software patching practices can work in concert with these hardening techniques to help further address computer risks. Follow these guidelines to help reduce risk:
- Disable software automatic updating services on PCs
- Inventory target computers for applications, and software versions and revisions
- Subscribe to and monitor vendor patch qualification services for patch compatibility
- Obtain product patches and software upgrades directly from the vendor
- Pre-test all patches on non-operational, non-mission critical systems
- Schedule the application of patches and upgrades and plan for contingencies
- Application Security – This refers infusing industrial control system applications with good security practices, such as a Role Based Access Control System, which locks down access to critical process functions, force username/password logins, combinations, etc.
- Device Hardening – Changing the default configuration of an embedded device out-of-the-box can make it more secure. The default security settings of PLCs, PACs, routers, switches, firewalls and other embedded devices will differ based on class and type, which subsequently changes the amount of work required to harden a particular device. But remember, a chain is only as strong as its weakest link.
An IT MSP can aid an organization in transitioning towards a defense in depth strategy in three major ways. IT MSPs are able to chart a course for the organization, so that they can better transition to this type of strategy without business disruption. IT MSPs can also identify the best technology, using their advanced knowledge of current cyber security measures and the threats that the organization is most likely to face. Finally, IT MSPs can leverage the power of cloud solutions to provide a defense in depth strategy that isn’t going to utilize more resources than the organization has access to. Without cloud-based infrastructure, most defense-in-depth strategies would be prohibitively expensive in terms of infrastructure and resource costs.
