Following with “Whitelisting” topic for protecting industrial computers, today we will talk about the step before its configuration, and how to protect our systems with Kaspersky´s KICS for Nodes solution.
Once we have deployed KICS for Nodes modules, the next step is to make an inventory of the software installed on these computers to permit or deny its execution. As mentioned in the post named “KICS for Nodes, Parte II” before that, we have to proceed with an antivirus scan to be sure that the target host is not infected by any piece of malware. If this occurs and it is under a running process, it could be authorized in the whitelist.
For this reason, we will set up a task to scan the system before creating a Whitelist. However, this step must be done keeping in mind that we can impact negatively on the host´s performance when the antimalware software starts to analyze the system. And, of course the tasks related with the process under control.
First of all, we will select the task called “On demand Scan”.
Then you must specify which areas will be analyzed and apply security level. Keep in mind that a deeper inspection will consume more hardware and system resources and take more time.
By default, there are a set of predefined profiles that includes more or less actions during the scan.
Nevertheless, it is possible to make a customized profiles by defining a lot of parameters according your preferences. You will find it in the “General”, “Actions” and “Performance” tabs and in all subset parameters, as you can see in pictures below. It includes what to do if a piece of malware is detected, objects to scan, extensions, and so on.
Here I will point out the “Excluded Files” option. The first analysis that it is recommended, is to scan the hard disc drives as much as possible to find a malware. But once we do it, a re scan of some folders which have a large number of files, could not be needed. For example, SIEMENS TIA Portal software suite that can occupy several gigabytes in the installed modules. If we do it and reduce the time scan, we must assume that if there is a piece of malware in that folder it will not be detected.
Finally we will enable or disable the heuristic module and if it is activated how must, it will works to find code that is not in the antivirus database.
When everything is defined the task will be ready to be applied. According to the enabled features, light or deeper analysis, among other configurations, will determine the time needed to complete the scan will be short or long.
But it is not this aspect on I want to focus on, at the time. I want to show you how an antivirus scan can impact on system behavior, and the amount of resources that could be consumed. In the picture below you can see a idle PC with SIEMENS TIA portal V13, Schneider Electric, installed. The usage of CPU can vary from 1 to 10 percent or even 0 percent when I took the screenshot. The memory has a baseline around 2 GB.
But what happens when the scan starts? The CPU usage increases to 96 percent.
After several seconds we can see that the memory increases and the CPU consumption can vary but is constantly high around 80-90 percent.
This is very important to notice because if we run an antivirus scan, we could impact negatively on system´s resources and in consequence the tasks associated to the industrial process.
This is one reason about why we must be aware how to run some tasks on systems, and why is important to schedule them or configure them with other features.
As we know some facilities and industries work 24x7x365 and do not stop their activities unless is necessary for production, preventive maintenance or other mandatory tasks. For these reasons sometimes will not have a time window to run an Antivirus scan, so we could be forced to run it without impacting on the performance during operation hours.
If this occurs, we are able to check “Perform task in background mode” in the task options. Doing this, we will modify and reduce the task priority in the operating system.
For a better understanding, following the complete description of this feature that you can find in the KICS for Nodes Administrator´s Guide
The check box modifies the priority of the task.
If the check box is selected, the task priority in the operating system is reduced. The operating system provides resources for performing the task based on the CPU load and protected device file system load from other Kaspersky Industrial CyberSecurity for Nodes tasks and other applications. As a result, task performance will decrease during periods of increased loads and will increase at lower loads.
If the check box is cleared, the task will start and run with the same priority as the other Kaspersky Industrial CyberSecurity for Nodes tasks and other applications. In this case, the task performance increases.
The check box is cleared by default.
That’s all for now, stay tuned for the next one.