It suddenly occurred to me to wonder where Antivirus programmers (like AVG, Avira, Kaspersky etc) get their data, ie, their antivirus signatures, from.

I mean, when you think about it, it doesn't seem logical that each of the dozens of antivirus program manufacturers needs a  research team, whose job it is to create AV databases and keep them up-to-date. Huge duplication of effort, I reckon.

It seems more likely that there's just one or two large companies in the background, who specialize in providing the software makers with their information.

Anyone know?