MITRE ATT&CK Technique
Command and Control T1571
Description

Adversaries may communicate using a protocol and port pairing that are typically not associated. For example, HTTPS over port 8088(Citation: Symantec Elfin Mar 2019) or port 587(Citation: Fortinet Agent Tesla April 2018) as opposed to the traditional port 443. Adversaries may make changes to the standard port used by a protocol to bypass filtering or muddle analysis/parsing of network data. Adversaries may also make changes to victim systems to abuse non-standard ports. For example, Registry keys and other configuration settings can be used to modify protocol and port pairings.(Citation: change_rdp_port_conti)

Supported Platforms
ESXi Linux macOS Windows
Created

April 29, 2026

Last Updated

April 29, 2026

STIX Data
{'created': '2020-03-14T18:18:32.443Z',
 'created_by_ref': 'identity--c78cb6e5-0c4b-4611-8297-d1b8b55e40b5',
 'description': 'Adversaries may communicate using a protocol and port pairing '
                'that are typically not associated. For example, HTTPS over '
                'port 8088(Citation: Symantec Elfin Mar 2019) or port '
                '587(Citation: Fortinet Agent Tesla April 2018) as opposed to '
                'the traditional port 443. Adversaries may make changes to the '
                'standard port used by a protocol to bypass filtering or '
                'muddle analysis/parsing of network data.\n'
                '\n'
                'Adversaries may also make changes to victim systems to abuse '
                'non-standard ports. For example, Registry keys and other '
                'configuration settings can be used to modify protocol and '
                'port pairings.(Citation: change_rdp_port_conti)',
 'external_references': [{'external_id': 'T1571',
                          'source_name': 'mitre-attack',
                          'url': 'https://attack.mitre.org/techniques/T1571'},
                         {'description': 'Gardiner, J.,  Cova, M., Nagaraja, '
                                         'S. (2014, February). Command & '
                                         'Control Understanding, Denying and '
                                         'Detecting. Retrieved April 20, 2016.',
                          'source_name': 'University of Birmingham C2',
                          'url': 'https://arxiv.org/ftp/arxiv/papers/1408/1408.1136.pdf'},
                         {'description': 'Security Response attack '
                                         'Investigation Team. (2019, March '
                                         '27). Elfin: Relentless Espionage '
                                         'Group Targets Multiple Organizations '
                                         'in Saudi Arabia and U.S.. Retrieved '
                                         'April 10, 2019.',
                          'source_name': 'Symantec Elfin Mar 2019',
                          'url': 'https://www.symantec.com/blogs/threat-intelligence/elfin-apt33-espionage'},
                         {'description': 'The DFIR Report. (2022, March 1). '
                                         '"Change RDP port" #ContiLeaks. '
                                         'Retrieved September 12, 2024.',
                          'source_name': 'change_rdp_port_conti',
                          'url': 'https://x.com/TheDFIRReport/status/1498657772254240768'},
                         {'description': 'Zhang, X. (2018, April 05). Analysis '
                                         'of New Agent Tesla Spyware Variant. '
                                         'Retrieved November 5, 2018.',
                          'source_name': 'Fortinet Agent Tesla April 2018',
                          'url': 'https://www.fortinet.com/blog/threat-research/analysis-of-new-agent-tesla-spyware-variant.html'}],
 'id': 'attack-pattern--b18eae87-b469-4e14-b454-b171b416bc18',
 'kill_chain_phases': [{'kill_chain_name': 'mitre-attack',
                        'phase_name': 'command-and-control'}],
 'modified': '2025-10-24T17:49:14.187Z',
 'name': 'Non-Standard Port',
 'object_marking_refs': ['marking-definition--fa42a846-8d90-4e51-bc29-71d5b4802168'],
 'revoked': False,
 'spec_version': '2.1',
 'type': 'attack-pattern',
 'x_mitre_attack_spec_version': '3.2.0',
 'x_mitre_deprecated': False,
 'x_mitre_detection': '',
 'x_mitre_domains': ['enterprise-attack'],
 'x_mitre_is_subtechnique': False,
 'x_mitre_modified_by_ref': 'identity--c78cb6e5-0c4b-4611-8297-d1b8b55e40b5',
 'x_mitre_platforms': ['ESXi', 'Linux', 'macOS', 'Windows'],
 'x_mitre_version': '1.3'}
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