Compromise Ground System: Malicious Commanding via Valid GS
Adversaries may use a compromised, mission-owned ground system to transmit legitimate-looking commands to the target spacecraft. Because the ground equipment is already configured for the mission, correct waveforms, framing, dictionaries, and scheduling, the attacker’s traffic blends with routine operations. Initial access unfolds by inserting commands or procedures into existing timelines, modifying rate/size limits or command queues, or invoking maintenance dictionaries and rapid-response workflows that accept broader command sets. Pre-positioned scripts can chain actions across multiple passes and stations, while telemetry routing provides immediate feedback to refine follow-on steps. Exfiltration can be embedded in standard downlink channels or forwarded through gateways as ordinary mission data. The distinguishing feature is that command origin appears valid, transmitted from approved apertures using expected parameters, so the first execution event is not a protocol anomaly but a misuse of legitimate command authority obtained through the compromised ground system.
Other Subtechniques of Compromise Ground System ( 2 )
Establish policy and procedures to prevent individuals (i.e., insiders) from masquerading as individuals with valid access to areas where commanding of the spacecraft is possible. Establish an Insider Threat Program to aid in the prevention of people with authorized access performing malicious activities.
Utilize a two-person system to achieve a high level of security for systems with command level access to the spacecraft. Under this rule all access and actions require the presence of two authorized people at all times.
A component of cybersecurity to deny unauthorized persons information derived from telecommunications and to ensure the authenticity of such telecommunications. COMSEC includes cryptographic security, transmission security, emissions security, and physical security of COMSEC material. It is imperative to utilize secure communication protocols with strong cryptographic mechanisms to prevent unauthorized disclosure of, and detect changes to, information during transmission. Systems should also maintain the confidentiality and integrity of information during preparation for transmission and during reception. Spacecraft should not employ a mode of operations where cryptography on the TT&C link can be disabled (i.e., crypto-bypass mode). The cryptographic mechanisms should identify and reject wireless transmissions that are deliberate attempts to achieve imitative or manipulative communications deception based on signal parameters.
Utilizing techniques to assure traffic flow security and confidentiality to mitigate or defeat traffic analysis attacks or reduce the value of any indicators or adversary inferences. This may be a subset of COMSEC protections, but the techniques would be applied where required to links that carry TT&C and/or data transmissions (to include on-board the spacecraft) where applicable given value and attacker capability. Techniques may include but are not limited to methods to pad or otherwise obfuscate traffic volumes/duration and/or periodicity, concealment of routing information and/or endpoints, or methods to frustrate statistical analysis.
In addition to authentication on-board the spacecraft bus, encryption is also recommended to protect the confidentiality of the data traversing the bus.
Provide additional protection modes for commanding the spacecraft. These can be where the spacecraft will restrict command lock based on geographic location of ground stations, special operational modes within the flight software, or even temporal controls where the spacecraft will only accept commands during certain times.
This countermeasure is focused on the protection of terrestrial assets like ground networks and development environments/contractor networks, etc. Traditional detection technologies and capabilities would be applicable here. Utilizing resources from NIST CSF to properly secure these environments using identify, protect, detect, recover, and respond is likely warranted. Additionally, NISTIR 8401 may provide resources as well since it was developed to focus on ground-based security for space systems (https://csrc.nist.gov/pubs/ir/8401/final). Furthermore, the MITRE ATT&CK framework provides IT focused TTPs and their mitigations https://attack.mitre.org/mitigations/enterprise/. Several recommended NIST 800-53 Rev5 controls are provided for reference when designing ground systems/networks.
Monitor defined telemetry points for malicious activities (i.e., jamming attempts, commanding attempts (e.g., command modes, counters, etc.)). This would include valid/processed commands as well as commands that were rejected. Telemetry monitoring should synchronize with ground-based Defensive Cyber Operations (i.e., SIEM/auditing) to create a full space system situation awareness from a cybersecurity perspective.
Employ physical security controls (badge with pins, guards, gates, etc.) to prevent unauthorized access to the systems that have the ability to command the spacecraft.
Utilize on-board intrusion detection/prevention system that monitors the mission critical components or systems and audit/logs actions. The IDS/IPS should have the capability to respond to threats (initial access, execution, persistence, evasion, exfiltration, etc.) and it should address signature-based attacks along with dynamic never-before seen attacks using machine learning/adaptive technologies. The IDS/IPS must integrate with traditional fault management to provide a wholistic approach to faults on-board the spacecraft. Spacecraft should select and execute safe countermeasures against cyber-attacks.  These countermeasures are a ready supply of options to triage against the specific types of attack and mission priorities. Minimally, the response should ensure vehicle safety and continued operations. Ideally, the goal is to trap the threat, convince the threat that it is successful, and trace and track the attacker — with or without ground support. This would support successful attribution and evolving countermeasures to mitigate the threat in the future. “Safe countermeasures” are those that are compatible with the system’s fault management system to avoid unintended effects or fratricide on the system.
A legitimate command sent to the spacecraft at an unexpected or inappropriate time, potentially causing disruption to normal operations. This could potentially lead to impacting system availability. This could involve commands such as executing an orbit adjustment or resource-intensive task outside of planned windows, thereby affecting the mission's overall availability or operational efficiency.
[x-opencti-command-log:command_type = 'legitimate_command' AND x-opencti-command-log:timestamp != 'expected_time']
Detection of an unexpected sensor state change in critical spacecraft sensors (e.g., Sun Sensor, GPS Sensor). The sensor states are modified outside of authorized operational windows, suggesting a malicious attack affecting the sensor's behavior.
[x-opencti-sensor:state = 'off' AND x-opencti-sensor:state_change_time != 'authorized_time']