View difference between Paste ID: QSmSr3zP and E90VdmHH

 local function drawScreen()
   term.setBackgroundColor(colors.blue)
   term.setTextColor(colors.white)
   term.clear()
   term.setCursorPos(1, 1)
   print("LuaGuard by SxwCorp CyberSecurity")
   term.setBackgroundColor(colors.lime)
   term.clearLine()
   term.setCursorPos(1, 3)
   term.setBackgroundColor(colors.blue)
 end
 
 local definitions = http.get("http://files.fluidnode.com/public/computercraft/LuaGuard/definitions.lua")
 
 local oldLoadstring = loadstring
 
 local function scanString(str)
   local hasFound = nil
   for k, v in pairs(definitions) do
     local found = str:find(v.fragment, 1, true)
     if found then
       hasFound = v.name
     end
   end
 
   if hasFound then
     drawScreen()
     print("Close call!")
     print("Your computer was almost infected with:")
     print(hasFound)
     print("LuaGuard has nullified the threat.")
     print("You're safe.")
     local random = tostring(math.random())
     os.queueEvent("luaguard_" .. random)
     os.pullEvent("luaguard_" .. random)
     print("")
     print("[Press any key to continue]")
     os.pullEvent("key")
   else
     return true
   end
 end
 
 local function fakeLoadstring(theCode, stringName)
   local run = scanString(theCode)
   if run then
     return oldLoadstring(theCode, stringName)
   else
     return nil, "LuaGuard virus prevention triggered"
   end
 end
 
 local function fakeLoadfile(filename)
   local fh = fs.open(filename, "r")
   if fh then
     local func = fakeLoadstring(fh.readAll())
     return func
   end
 end
 
 local function fakeDofile(filename)
   local f = assert(fakeLoadfile(filename))
   return f()
 end
 
 local function fakeOSrun( _tEnv, _sPath, ... )
     local tArgs = { ... }
     local fnFile, err = fakeLoadfile( _sPath )
     if fnFile then
         local tEnv = _tEnv
         --setmetatable( tEnv, { __index = function(t,k) return _G[k] end } )
         setmetatable( tEnv, { __index = _G } )
         setfenv( fnFile, tEnv )
         local ok, err = pcall( function()
             fnFile( unpack( tArgs ) )
         end )
         if not ok then
             if err and err ~= "" then
                 printError( err )
             end
             return false
         end
         return true
     end
     if err and err ~= "" then
         printError( err )
     end
     return false
 end
 
 if definitions then
   definitions = loadstring(definitions.readAll())()
   loadstring = fakeLoadstring
   loadfile = fakeLoadfile
   dofile = fakeDofile
   os.run = fakeOSrun
 else
   drawScreen()
   print("Hello! LuaGuard was unable to fetch virus definitions.")
   print("Your computer will boot in unsafe mode")
   print("")
   print("[Press any key to continue, or ctrl-R to reboot]")
   os.pullEvent("key")
 end
 
 local function transparent()
   local oldfs = {}
   oldfs.open = fs.open
   oldfs.delete = fs.delete
   oldfs.move = fs.move
   oldfs.copy = fs.copy
   oldfs.exists = fs.exists
   oldfs.combine = fs.combine
   oldfs.list = fs.list
   local oldos = {}
   oldos.pullEventRaw = os.pullEventRaw
 
 
   local function redirect(path)
       if oldfs.combine("/", path) == "startup" then
           return "/.luaguardstartup"
       else
           return path
       end
   end
 
   fs.open = function(path, mode)
       return oldfs.open(redirect(path), mode)
   end
 
   fs.delete = function(path)
       return oldfs.delete(redirect(path))
   end
 
   fs.move = function(path, dest)
       return oldfs.move(redirect(path), redirect(dest))
   end
 
   fs.copy = function(path, dest)
       return oldfs.copy(redirect(path), redirect(dest))
   end
 
   fs.exists = function(path)
       return oldfs.exists(redirect(path))
   end
 
   fs.list = function(path)
       if oldfs.combine("/", path) == "" then
           if oldfs.exists("/.luaguardstartup") then
             local list = oldfs.list("/")
             local newlist = {}
             for k, v in pairs(list) do
                 if v ~= oldfs.combine("/.luaguardstartup", "/") then
                     table.insert(newlist, v)
                 end
             end
             return newlist
           else
               local list = oldfs.list("/")
               local newlist = {}
               for k, v in pairs(list) do
                   if v ~= "startup" then
                       table.insert(newlist, v)
                   end
               end
               return newlist
           end
       else
           return oldfs.list(path)
       end
   end
 end
 
 transparent()
 print("LuaGuard active")
 
 if fs.exists("/startup") then
   term.setTextColor(colors.white)
   shell.run("/startup")
 end