Thanks for the responses, both. In answer:-
I don't know what "vitakey" is and have not downloaded it. (The folder containing it was created in 2010, according to my windows file explorer).
If it is a "false positive" then should it not have been picked up (a) in a previous full scan done about two months ago (when I first installed Kaspersky Total Security) and/ or (b) during real-time scanning?
I have emailed technical support with a full description of this issue, together with screenshots (exports of scan reports) and "Get System Info". (By the way, what is "Get System Info" as it seems to contain a huge amount of data and information about me/ my computer and I am wondering if it is all relevant and/ or necessary?).
The screenshot in my earlier message was from Kaspersky Total Security.
The events logged in Kaspersky in relation to "vitakey" are documented in the scan reports (such as the screenshot I provided previously). There are nine entries in total, the only difference being that "KHLB0" in the path has a "KHLB1" version and a "KHLB2" version as well - and there are three of each: one that says "detected" (for each of KHLB0, KHLB1 and KHLB2), and again for each one that says "quarantined" and a final one that says "deleted".
As I don't know what "vitakey" is I don't believe I have any software installed in relation to it.
The only path that I have found that leads to anything relating to "vitakey" is the one in the screenshot I provided. However, that path still exists and there is still an existing file in the same folder from which Kaspersky deleted the file SDKInstaller.exe. So, what still exists on my computer is the following:
As one can see, it follows the exact path as the "trojan" file that was detected, quarantined and deleted by Kaspersky. The only difference is that the name is different (InstallSDK64.exe as opposed to the deleted file name of SDKInstaller.exe).
As the "trojan" file was deleted, and therefore no longer appearing in windows file explorer, it does not seem that there is any way to establish a "date modified" for it, which would have given us a clue as to how long it had been present on my computer.
And again, as the file no longer exists it does not seem there is any way to scan the individual file using "virusdesk". It seems to have been automatically deleted as part of the full scan process.
Thanks again both for your engagement and effort to help.