How to Ensure a critical PLC system is free from viruses

How to Ensure a critical PLC system is free from viruses or not malfunction beyond the original program in future . 

Is thee any viruses scanner for PLC? 

I am talking about a PLC based critical life saving system from H2S toxic gas and methane leakage in Oil&Gas sector. 

How to distinguish an issue happening with virus or other case? Nowadays program errors also blame to virus? How to prove a malfunction happened not due to virus? 

What can we do to avoid such a situation in the below link🤔❓

Now doubts comes to the end user after this

news. How to convince them? 

  Split from:virus infection on siemens PLC & Networks

HEllo,

Read the articles that I attached earlier, on your last topic ...

Scanning PLC for viruses is difficult, for the simple reason that the virus itself can be downloaded without changing the program code, it can be downloaded without changing the total amount of occupied program space - this is all theory, and part of the practice from the article in my answer.

However, you can try the following.

1. I'm not talking about the first security requirements - both network and hardware.

2. You can independently check the volumes and checksums of the blocks of your program inside the PLC - and display all this information in the SCADA system

3. On the basis of your firewall or switch, you can check the network for unauthorized network activity when one of the network patrons suddenly starts violently scanning the network (this is a call ...)

4. the most oak, but in theory a reliable method - to downloading the PLC program on shedule - like maintanence service. When rewriting, you will erase, everything unnecessary inside, and write only the right ...

But, my opinion is that it is better to carefully prepare for an attack than to fight in the process.

Viruses do not appear at special facilities just like that, believe me, this is not an accident - and you need to be prepared for it.

Thanks for reply.

Is it possible to know it through plc diagnostic function?

If the program change and its size not changed, then what to do?

How does this firewall works?

If someone tell their plc is virus infected and plant shutdown with production lossless. Does siemens defend it?

Does they have any facility to  prove that it was a program error or not virus infected?

If a virus that not cause program volume change but really change program , what to do?

Hello,

really don't understand to your strategy with cyclical asking about this problematic to obtain deeper and deeper very specific know-how infos. With that your previous Virus Topic you have good enough infos about that. In other case you need call some professional corporation or in case to know system specific infos, need call Support. Simply this forum is helping to general problems with programming and ask this kind of question is really strange to me, sry...

Thanks for reply.

S7 controllers are safe, I know, it's firmware having internal firewall to protect from virus.

Thanks for reply.

Do PLC can resist virus infection like anti-virus software?

Wow .... Siemens must be terrified of you and your contributions.

Edit:

And changed the post again:

You act like a little child. You change the content of your posts afterwards. But not to add statements, but to absolutely change the meaning or to delete statements.
As a result, any subsequent contributions lose their meaning, like my contribution here.
I will quote your posts soon. You cannot change the quotation then.

Your statement was analogous:
Siemens blocked my public IP after I wrote topics that Siemens didn't like.

JKV JAMES

My laptop's public Ip has been blocked from Siemens Forum after posting this thread and can access the forum content only from another ip. Why this block?

Added a thread on the issue

All the posts about viruses on PLC are only for welfare of Siemens Automation and 1600 trusted channel partners who all are depending these PLCs.Moreover, I need  to convience my customers after getting answer from this forum before reaching a situation of their query to a legal dispute upon their production loss. 

Ensure the safety of PLCs or reply that these PLCs are safe due to these and these reason. That is courage.

Otherwise people think that weak leadership in Siemens as they feared and taken a wrong decision to block public ip of a forum member who made 250+ posts by spending his valuable time and received many thanks for his posts from other forum members.

 hi,

Well, the truth is, you are asking tricky questions here, and trying to get simple answers to them.
You say that your customers trust you and If they look at our forum and our answers, then their trust will only become more to you and your projects ... It is unlikely, this is true ...

If you want advice - write to Siemens on behalf of your company - specific questions and specific problems - get an answer.

I would do so, and do when I understand that the answer will be the question will be too complicated ... Moreover, the official conclusion from the manufacturer is the best answer.

However, as our other colleagues said, common questions are solved here, simple answers and opinions are received - this does not mean that all the answers here are the true truth, that’s why the topic you started may seem suspicious, just like all the answers in it ...

We gave you a recommendation, we are not entitled to give you a guarantee ...

QUESTIONS ARE PUBLIC. SO WE USE FORUM TO DISCUSS. 

This is a basic question one customer asked while proposing a PLC to their critical system . This question coming from other  companies whom already installed same system with siemes PLCs from other vendors in many their plants. 

There is nothing suspecious. I am posting on Siemens website. Whomever have knowledge they can answer. This is the question everyone want to know who wish to  buy siemens PLC. If they wish to answer confidential , let them to message me in my inbox.

I have attached a news link above about virus infection on PLC in United Kingdom in 2017. My one another post about Strux virus infection in Iran's Power plant and Siemens accepted the same in around 8years back 2012 as per Wikipedia. 

So the customer companies got doubt that these PLCs are unsafe for their critical system in their plant and a virus infection in PLC can cause more critical in their plant or they may shutdown their production. 

1)What justification can Siemens give that the new PLC will not infect virus? What safety system added in PLC after 2012 and 2017 virus infection news which I have attached above link?

2)Do they confident to take responsibility if production loss happens in future due to virus attack on PLC which you were accepted as per Strux virus details in Wikipedia?

3)My question: Do Siemens PLCs got any features to distinguish a virus infection and a programming error? 

How did it confirm to accept that PLCs in Iran's Powerplant infected with Strux virus? This is for distinguishing program error and real virus. Otherwise many news may come about exaggerated PLC virus infection on Siemens PLCs. 

4)why did this thread lead to block my public ip of laptop to this forum access? What is the purpose of forum if blocking someone who express thier queries with courageous ?

JKV JAMES

4)why did this thread lead to block my public ip of laptop to this forum access? What is the purpose of forum if blocking someone who express thier queries with courageous ?

 Do you actually believe the nonsense that you write here?