Well, I guess if you use the term losely. Since I consider some spyware so aggressive and well hidden that I've seen some viruses that are easier to remove. And then there is malware...blah blah. You know. It usually due to them surfing to sites they shouldn't...not necessarily porn, but like games and looking for free ringtones. Those are often times riddled with spyware and malware...even though I don't know the technical difference in those two.
To me it's like a Mild to Medium to Bad would be Spyware to Malware to Virus. But it all really runs together to me. They are all just programs designed to give someone the blues