VirusMod is a Minecraft Mod of which introduces different virus variants into the game.
Currently the viruses stem off the idea of bacteria, raw meats and slime causing a rather absurd outcome of a strain of a virus which can cause mass destruction.
Code wise, the main block you place is the "host" of the virus, it's the central hub of which contains the TileEntity, this contains how long it'll last, and the 'logic' of the virus.
Some credits are towards the BacteriaMod as I initally liked the mods idea and wanted to stem off of it. I in no way intended to copy any of their work and respectfully never used any of their code.