neowin[.]net/news/newly-discovered-pc-malware-version-spreads-through-wi-fi-networks
Known malware picked up a new capability -- once it infects a system through the usual routes, e.g. malware-laced spam, it finds all available WiFi networks, then tries to brute force login to those networks, parsing a list of common passwords. If it succeeds, it phones home for directions & downloads, and tries to infect every device connected to that network.
What makes this a bit worse than the usual malware is that it does not depend on you opening an email attachment or visiting a web site or downloading something you maybe shouldn't -- you could practice really safe computing and still get hit if one of your neighbors is careless. Rather than just go after anything connected to the same network as the infected PC, it goes after any & every WiFi network it can find, including yours. Generally if you can "see" a WiFi network, whomever owns that network can see yours, so a quick check of the available WiFi networks might give you an idea of your risk of being attacked. I can see well over a dozen WiFi networks -- their signal reaches this PC's WiFi antennae -- so I figure the odds are pretty good that in at least one of those households there's an idiot whose risky behavior could get them infected. A small, free app will give you more info than what Windows displays:
nirsoft[.]net/utils/wifi_information_view.html