Module: TurboRex::MSRPC::RPCFinder::StaticRPCBacktracer

Includes:
Utils::DisassemblerHelper
Included in:
ImageFinder
Defined in:
lib/turborex/msrpc/rpcfinder.rb

Overview

This module provides a set of helper functions that backtracking RPC runtime routines parameters to determine information such as address of security callback function and rpc flags.

Instance Method Summary collapse

Methods included from Utils::DisassemblerHelper

#_disassemble_executable_sections, #add_dasm_all_method, #addrtolabel, #backtrace, #solve_cppobj_call, #solve_guard_icall

Instance Method Details

#bt_security_callback(dasm, trace_flags = false, uuid = nil) ⇒ Object

RpcServerRegisterIf2/RpcServerRegisterIf3/RpcServerRegisterIfEx



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# File 'lib/turborex/msrpc/rpcfinder.rb', line 14

def bt_security_callback(dasm, trace_flags=false, uuid=nil)
  res = []

  case dasm.cpu.size
  when 64
    expr_if_handle = 'rcx'
    expr_sec_cb = '[rsp+30h]'
    expr_flag = 'r9' if trace_flags
    mk_struct_proc = Proc.new {
      TurboRex::MSRPC::RPCBase::RPC_SERVER_INTERFACE64.make(pack: 8, align: true)
    }
  when 32
    expr_if_handle = '[esp]'
    expr_sec_cb = '[esp+14h]'
    expr_flag = '[esp+Ch]' if trace_flags
    mk_struct_proc = Proc.new {
      TurboRex::MSRPC::RPCBase::RPC_SERVER_INTERFACE32.make(pack: 4, align: true)
    }
  end

  fn = ['RpcServerRegisterIf2', 'RpcServerRegisterIf3', 'RpcServerRegisterIfEx']
  fn.each do |f|
    callers = dasm.call_sites(Metasm::Expression[f])
    callers.each do |addr|
      server_if = mk_struct_proc.call
      if_handle = backtrace(addr, dasm, expr_if_handle).first.first

      next unless raw = dasm.read_raw_data(if_handle, server_if.slength)
      server_if.from_s(raw) 
      interface_id = TurboRex::MSRPC::Utils.raw_to_guid_str(server_if['interfaceId'].to_s)

      found, _ = backtrace(addr, dasm, expr_sec_cb)
      found_flags, _ = backtrace(addr, dasm, expr_flag) if trace_flags
      if dasm.get_section_at(found.first)
        r = {interface_id: interface_id, callback: found.first}
        r[:flags] = found_flags.first.to_i if trace_flags
        res << r
      end
    end
  end

  res.uniq!

  case uuid
  when String
    return res.select {|r| r[:interface_id] == uuid}
  when Array
    return res.select { |r| uuid.include?(r[:interface_id])}
  else
    return res
  end
end