

Most malware authors are looking for the lowest-hanging fruit. "I don't have enough money/data/CPU power to be valuable to malware authors." It quietly infiltrates your system and starts sending your sensitive data to its controller. But even on a more subtle level, malware won't necessarily cause your network speed to grind to a halt or cause visibly wonky behavior.
LET IT DIE PC MALWARE MAC
You can't upload computer viruses to an alien spaceship from your Mac laptop, and they don't all come with images of laughing skulls. …Because Hollywood blockbusters are a solid place to go for factual information about computer security. "I'll know if I'm infected because malware is noisy." Always remember to stop, move your cursor away from that attachment, and check with the sender before opening it! Email still remains a very common attack vector, and people are still being scared or enticed into opening unexpected attachments. And yet, people are still blindly opening unexpected attachments that appear to come from friends, family, or trusted companies. It was a large-scale malware that spread via email, appearing as if it had been sent by someone in your address book (so, probably by someone you know and trust). Remember that whole Melissa virus thing that happened about 14 years ago? That one did make the evening news. "I can safely open this attachment because it appears to be from my friend/family/trusted authority." Avoiding the "dark and seedy corners of the Internet" is no longer a sufficient enough measure to keep your computer malware-free. Your friend's blog, that site with all the cute kitten pictures, even some fairly major reputable websites get hit and start serving up malware. A lot of the more problematic malware events of the past few years have been due to compromised, legitimate websites, especially if they use ad networks.

LET IT DIE PC MALWARE SOFTWARE
Sites for sharing pirated software are definitely not part of a safe Internet experience, but porn sites can actually be safer for your computer than you might imagine. "I can protect myself from malware by not going on porn/warez sites." You gotta keep your head down if you're gonna get that cash! That was the ostensible purpose of Flashback, but because they got too big too quickly, they got noticed and emerged with nothing. Financially motivated malware is big business that operates much like a software company in that groups of individuals cooperate and have separate responsibilities in creating and distributing malware. That may still be true on the hacking side of things, but nowadays malware is largely all about the Benjamins, as they say.
LET IT DIE PC MALWARE SKIN
I can't really speak to the skin condition of today's malware writers, but they're sure not infecting people for the lulz anymore.

"Malware is created by pimply teenagers simply for bragging rights."
