As Kevin (Carp) alluded upon, fonts can get onto your computer through a number of ways besides direct installation. Websites and programs can install them -- the DVD font was probably installed by a dvd software or plugin you have. If not that, as Kevin said, probably a website you visited. As a designer, I can personally never get enough fonts =P If they're decent fonts, I wouldn't worry about how they came to be, just worry about making sure they're virus-free.
Originally posted by Carp Can a font have a virus?
I doubt it.
IWDN - Really smart web developers... and me!
More than any time in history mankind faces a crossroads.
One path leads to despair and utter hopelessness, the other to total extinction.
Let us pray that we have the wisdom to choose correctly.