Tag Archives: SCADA/ICS networks

Chernobyl hit by Petya/NotPetya

2 July 2017

The short post New Ransomware Crippling Chernobyl Sensors published on 28 June 2017 by Jack Laidlaw at HACKADAY deeply frightened me. I was relieved to read, that no Industrial Control Systems (ICS) were affected.

Picture Credits: Chernobyl NPP Press Center, chnpp.gov.ua

ICS at the Chernobyl Power Plant. Picture Credits: Chernobyl NPP Press Center, chnpp.gov.ua

The following press statement was published at the Power Plants homepage:

As of 27.06.2017 due to the cyber attack: the SSE ChNPP’s official website was not accessible, servers for controlling the local area network and auxiliary systems of SSE ChNPP information resources (mail server, file-sharing servers, Internet resources’ access server, electronic document flow system server) were switched off. There was partial failure in operation of personal computers of workplaces of operators of individual radiation monitoring systems without loss of the control function as a whole.

From the recent cyber-attacks on industrial systems we know, that the attacks always start in the office network of a production site. Once an office computer is hijacked, the cyber criminals use it as a base to further probing the network until they find a weakness in the network configuration which allows them to attack the production network.

Thus, we should not take this matter lightly. In my opinion, the production network of nuclear power plants must be fully isolated from the office network, and the internet. Period.

Have a good week.

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Some thoughts on “Ransomware a real risk for SCADA networks”

5 June 2017

By now the ‘Air gapping’ myth should be expunged from every ICS/SCADA manager on earth.” I really like this statement from Daniel Cohen-Sason, published on 23 May 2017 in the CYBERBIT blog.

From my point of view, the ‘Air Gap’ era ended with the introduction of portable engineering stations about 30 years ago.

Modern OT networks are often designed on the basis of the ISA 95 Standard with network zones and security devices, e.g. firewalls, to control the communications flow between the process control and SCADA systems across the zones. Modern production requires a lot of Machine-to-Machine (M2M) communication between the production networks zones and between the production network and the business network. Besides this M2M communication Human-to-Machine (H2M) communication is required, e.g. for operator access from the business network and for remote maintenance.

For M2M and H2M interaction communication channels must be opened on the firewalls. With this, there is always a chance that malware can spread across such required connections. Furthermore, cyber attackers can gain access, e.g. through remotely exploitable vulnerabilities, after they hijacked a M2M communications endpoint in the business network. We dealt with this very effectively in the past 20 years.

Many of the required connections use the SMB protocol for exchange of data. That’s no problem per se. The problem is, that we still use Windows 7 and Windows Server 2008 in the manufacturing industry which cannot work with the latest versions of the SMB protocol for data exchange.

Since WannaCry exploited a vulnerability in SMB version 1.0, it was only a matter of time before WannaCry would find its way across a required connection from the business network to the production network.

How to deal with the problem?

  • Priority patching.

The systems at the border between the business network and the production network must me patched with highest priority. Although this is somewhat tricky to achieve in WSUS, it’s worth to deal with this WSUS feature. In addition to the operating system components, all application components must be patched as well. The same applies to Linux based systems.

  • Deactivating SMB.

Is a great means in the case of an emergency, and part of a long-term data exchange strategy.

  • Set up asset and vulnerability management.

At least all systems at the endpoints of required M2M and H2M connections must be included. This enables you to evaluate the scale of the problem in the case of a new vulnerability.

  • Faster innovation cycles.

At least for the systems at the perimeter of the production network we must allow for shorter innovation cycles. With Windows 8, Windows 10, and Windows Server 2012, new versions of the SMB protocol are used which are not affected by WannaCry. Don’t forget to deactivate the SMB V1.0 compatibility in the this versions.

This includes the technology used for data exchange. For example, the widely used Robocopy fosters the spreading of WannaCry because it is based on the SMB protocol.

  • Increase the level of isolation.

Start with challenging the required M2M and H2M connections. Eliminate every connection without a business purpose. For the remaining, check whether the best available security technology is used.

Take care!

Ransomware for Industrial Control System – Digital Carelessness

19 March 2017

Ransomware for Industrial Control Systems (ICS) is a scaring idea. The research paper ‘Out of Control: Ransomware for Industrial Control System‘ by David Formby, Srikar Durbha and Raheem Beyah from the Georgia Institute of Technology is really worth reading.

The researchers study several attack vectors and run a proof of concept (POC). In addition, they give some hints for mitigation of this new risk in the ICS / SCADA domain.

In the simplest case, if the PLC is connected to the internet, the cyber-criminal can attack the PLC directly. A more dangerous, but also very promising way is to start an attack on a workstation located in the corporate network and use this system as base camp for the access to the production network.

In the past weeks I prepared a speech for a workshop about “Safety and security in plant safety”. In the IIoT, the digital world acts upon the physical world. With this, flaws in the IIoT software may create a safety problem. For example, if a PLC or other SCADA components are attached to the internet, cyber criminals can exploit such flaws and compromise the integrity of the systems or implement ransomware on the systems. In the worst case, if e.g. the SCADA system controls a critical infrastructure like a power grid, this may result in a blackout. And operators of critical infrastructures will pay definitely any ransom to avoid a blackout.

The attack vectors described above are the native way for accessing industrial facilities and critical infrastructures. Besides the PLC, lots of other components like switches or HMI panels are connected more or less intentionally to the internet today. My colleague Christoph Thust from Evonik calls this the Digital Carelessness.

A plain SHODAN search for ‘SCALANCE‘ results in 213 hits. These network switches are more or less exposed to the internet. If a cyber attacker can hijack such a switch, he gains full control of the production network.

Shodan Scalance Search

Shodan Scalance Search. Click to enlarge.

A search for ‘SIMATIC HMI‘ results in 103 hits. This HMI panels are directly attached to the internet, lots of them can be viewed with WinVNC, some of them can be fully operated by EVERYONE.

Shodan Search HMI

Shodan Search HMI. Click to enlarge.

And, above all, HMI panels attached to the internet can be used as base camp for an attacker’s lateral movement in the production network.

Although ransomware is a really big issue today, the effort to rollout ransomware in a SCADA environment is high compared to the effort of plain attacks to unsecured SCADA system components.

The good news is, that the vendors of SCADA components already offer the elementary technology and strategies for their secure operation. But improvement of the basic security technologies is of crucial need for efficient use in the production domain.

The bad news is, that neither the engineering service providers nor the plant operators are fully aware of cyber-threats and their impact on plant operations and safety. The above examples make clear that the mitigation measures and defense strategies provided by the technology vendors are not followed.

From my point of view we need to start early in the construction process with considerations of cyber security. Security gates must be added to each construction phase. And during handover to the operator, a final pen test must be performed. As soon as Security by Design becomes an integral part of the Industrial Plant Life Cycle, the era of digital carelessness will end.

Have a good weekend.

If one can ping an industrial controller, one can stop it

12 November 2016

On Wednesday I watched the Indegy webinar “How a new PLC Simulator vulnerability can compromise SCADA/ICS networks?“. The webinar dealt with a recently detected vulnerability in a simulator software.

Simulators are used for verification and validation of changes to process control systems (PCS) before the changes are applied to the PCS. If the changes passes the tests it is very likely that the changes will have no negative impact on the PCS and thus to the safety of the process. Simulators are executed on the Engineering Station which is directly connected to the control system and to the production network.

PCS are very specialized realtime industrial computer systems. All PCS are lacking of the security features we know from the office IT, e.g. authorization, authentication and malware protection.

The slide below brings it straight to the point:

The Center of Gravity in the ICS Domain

The Center of Gravity in the ICS Domain

With this, the isolation of the Engineering Stations and the PCS in separate network zones is the key to security in the ICS domain. Access to these networks must be limited to authorized staff and through few strictly controlled access paths.

And with this, the first commandment of the Office IT Security, “Thou Shall Patch“, becomes less important in Industrial IT (OT) Security. “Thou Shall Isolate“, across the entire OSI stack, is the first commandment of OT Security.

Have a good weekend, and enjoy the webinar.