Anthrax

Source: Phys.org
There’s a reason that when the world’s most insane military supervillains went looking for a disease they could turn into a weapon, they settled on anthrax. It’s fast, lethal, and you can get anthrax just by touching something that has touched something that had anthrax spores on it in a sort of Six Degrees of Separation of Death.

The 2001 attacks . . . It was him all along!
Source: Bam Smack Pow
Initial symptoms of inhalation anthrax are, you guessed it, just like the flu. Except for the part where you die, which shouldn’t take longer than a few days. Play us out, obligatory Scott Ian reference:
“The horror of it all
The horror of it all
The horror of it all
The horror of it all
Say goodbye; it’s such a horror
My memories; there’s nothing harder
Anger and hatred fill the page
So smash the walls—it’s time to rage.”