PyDBG process snapshots not working

Question

I'm following Gray Hat Python book and have copied their code for the process snapshots using PyDBG. When I run the script I get no errors and expected output however my program is not actually reverting to the snapshot. When I go in debug it seems like values are in the snapshot variables as if it is storing snapshot info but I don't really know enough to say for sure.

Here is code:

from pydbg import *
from pydbg.defines import *
import threading
import time
import sys

class snapshotter(object):
    def __init__(self,exe_path):
        self.exe_path = exe_path
        self.pid = None
        self.dbg = None
        self.running = True

        pydbg_thread = threading.Thread(target=self.start_debugger)
        pydbg_thread.setDaemon(0)
        pydbg_thread.start()

        while self.pid == None:
            time.sleep(1)

        monitor_thread = threading.Thread(target=self.monitor_debugger)
        monitor_thread.setDaemon(0)
        monitor_thread.start()

    def monitor_debugger(self):
        while self.running == True:
            input = raw_input("Enter: 'snap','restore' or 'quit'")
            input = input.lower().strip()
            if input == "quit":
                print "[*] Exiting the snapshotter."
                self.running = False
                self.dbg.terminate_process()
            elif input == "snap":
                print "[*] Suspending all threads."
                self.dbg.suspend_all_threads()
                print "[*] Obtaining snapshot."
                self.dbg.process_snapshot()
                print "[*] Resuming operation."
                self.dbg.resume_all_threads()
            elif input == "restore":
                print "[*] Suspending all threads."
                self.dbg.suspend_all_threads()
                print "[*] Restoring snapshot."
                self.dbg.process_restore()
                print "[*] Resuming operation."
                self.dbg.resume_all_threads()

    def start_debugger(self):
        self.dbg = pydbg()
        pid = self.dbg.load(self.exe_path)
        self.pid = self.dbg.pid
        self.dbg.run()

exe_path = "C:\\WINDOWS\\System32\\calc.exe"
snapshotter(exe_path)

Answer 1

Your code worked for me on Python 2.7 on XP SP1 (Virtual machine). Which version of Windows are you running? Also, could it be your pydbg install? I'm using a binary I found at:

http://www.lfd.uci.edu/~gohlke/pythonlibs/#pydbg