Certain extensions of files. Sometimes, the name of the file could be something like Trojanx64.sys(I think). I had a few files of malware, but they were deleted. I believe the most common extension is .sys for viruses. Additionally, antivirus software could look into the properties of the program/process.
Answer:
You can go back to that point towards the end of the presentation or find where it would link later on in the presentation. Then you can ask if there are any questions and if the audience are willing to ask them you can go ahead and explain it.
Explanation:
do you want us to write something about it or??