The L-Virus is a computer-bug-like virus created by Leviathan.
Notable symptoms of this virus include red eyes, and an aggressive attitude to anyone who doesn't have the virus. Other symptoms include darker skin tones on some Appmon, and the Appmon's body is surrounded by faint black mist.
In some cases, the infected Appmon will also have no iris or pupil, and red outlines on the edges of the eyes.
The respective Appmon's App will also be affected in a crazy way.
After an infected Appmon loses against a non-infected Appmon in battle, they will be surrounded by 3 energy rings as a 3-second timer will countdown before the virus "poofs" out of the Appmon in the form of a white dust cloud. Once the cloud clears, the Appmon will appear non-infected before teleporting into an Applidrive, and turning into an Appmon Chip.
7code Appmon will have the same thing, only they will display a special orb of the color of their type, and they won't have the timer. When they come out of the cloud however, their entire body will turn golden.
In other cases, all the symptoms just fade off. First the mist fades, and the skin tone returns to normal. Then, the iris and pupils return as the Appmon's behavior returns to normal.
Many have described the cure as a sense of relaxation, and some have related it to something they enjoy.