Cisco's Talos research group outlined a malware threat that has already infected 500,000 routers in 54 countries from a variety of manufacturers, with code substantially overlapping with known Russian attacks.

Why it matters: The threat, nicknamed VPNFilter, can infect Linksys, MikroTik, NETGEAR and TP-Link small business and home office routers as well as network storage devices. It can steal web site credentials, monitor commands to industrial systems and launch destructive attacks against the devices it infects. And it can do all of this beyond the reach of many types of network defenses that don't protect routers.