This happens when a detection is accomplished through heuristics. There is no such thing as a heuristic virus. As a technical concept, everything in malware detection is done via heuristics.
Photosynthesis is the process in which plants (also autotrphoic protists and some bacteria) use light energy, from the Sun, to make sugars and organic food molecules from CO2 and water (H2O). This process is essential for the formation of not only energy, but also for the formation of glucose for purposes of structure.
The equation for photosynthesis is below. Now if you look at the product side (to the right of the arrow), you will see that two things are produced in photosynthesis: Oxygen and Glucose. However, the oxygen that is produced in photosynthesis is released to the enviroment, leaving you with glucose. So, photosynthesis basically produces oxygen to release into the enviroment, and a carbohydrate (gives energy) for the plant. So to answer your question, the main product in photosynthesis is a carbohydrate. Hope this helps!