PowerDNS LUA script which filters out malware domains (redirect to new IP or NXDOMAIN response)

baddomains.lua

baddomain = Set{
"retro-7-3.cz.cc.",
"x0a.in.",
"x0c.ru.",
"x1g.in.",
"x3b.ru.",
}

-- the actual file contains > 20k domains from malwaredomains.com

filterdomain.lua

function Set (list)
      local set = {}
      for _, l in ipairs(list) do set[l] = true end
      return set
end

dofile("/etc/powerdns/baddomains.lua")

function preresolve ( remoteip, domain, qtype )
        if baddomain[domain] then
                -- pdnslog ("prequery handler called for: "..remoteip.." on "..getlocaladdress().." for domain "..domain);
                return 0, {{qtype=pdns.A, content="1.2.3.4"}} -- redirect to an ip
                -- return pdns.NXDOMAIN, {} -- or NXDOMAIN, uncommment this and comment above to use NXDOMAIN
        end
        return -1, {}
end