Secondary/Backup Communication Channel: Receiver

Threat actors may target the spacecraft’s secondary (backup) RF receive path, often a differently sourced radio, alternate antenna/feed, or cross-strapped front end that is powered or enabled under specific modes. Threat actors map when the backup comes into play (safing, antenna obscuration, maintenance, link degradation) and what command dictionaries, framing, or authentication it expects. If the backup receiver has distinct waveforms, counters, or vendor defaults, the attacker can inject traffic that is accepted only when that path is active, limiting exposure during nominal ops. Forcing conditions that enable the backup, jamming the primary, exploiting geometry, or waiting for routine tests, creates the window for first execution. The result is a foothold gained through a rarely used RF path, exploiting differences in implementation and operational cadence between primary and standby receive chains.

ID: IA-0004.02
Sub-technique of:  IA-0004
Notional Risk (H | M | L):  24 | 21 | 17
Tactic:
Created: 2022/10/19
Last Modified: 2026/03/11

Countermeasures

ID Name Tiering Description NIST Rev5 ISO 27001 Onboard SV Ground
CM0009 Threat Intelligence Program A threat intelligence program enables an organization to systematically collect, analyze, and apply information about adversary capabilities, infrastructure, and intent to inform defensive priorities and drive risk-informed security decisions across the mission lifecycle. For space missions specifically, this may include leveraging available all-source intelligence services or commercial satellite imagery to identify and monitor adversary infrastructure development and acquisition activities that may signal emerging threats to mission assets. Threat intelligence outputs should be operationalized into concrete adjustments to defensive architecture, monitoring priorities, and incident response posture rather than treated as informational products alone. Direct countermeasures against adversary infrastructure identified through this program will fall outside the scope of the mission in the majority of cases; the primary value of the program is in generating actionable awareness that sharpens the organization's own defensive posture. PM-16 PM-16(1) RA-10 RA-3 RA-3(2) RA-3(3) SA-3 SA-8 SI-4(24) SR-8 A.5.7 A.5.7 6.1.2 8.2 9.3.2 A.8.8 A.5.7 A.5.2 A.5.8 A.8.25 A.8.31 A.8.27 A.8.28
CM0024 Anti-counterfeit Hardware Counterfeit electronic components represent a direct supply chain threat to space mission integrity, introducing hardware that may fail prematurely, perform outside specification, or contain malicious functionality deliberately embedded by an adversary during manufacture or distribution. A formal anti-counterfeit program must establish policy and procedures that span the entire component acquisition and integration lifecycle, from supplier qualification and procurement through incoming inspection, storage, and installation. The program must address two distinct but related risks: counterfeit components that fail to perform their intended function, degrading mission reliability; and deliberately tampered components that introduce malicious hardware functionality or create pathways for malicious code execution. Anti-counterfeit controls must include measures appropriate to component criticality and supply chain risk to authenticate components, detect evidence of tampering, and resist unauthorized modification. Detection and prevention must be treated as complementary objectives: prevention through qualified sourcing and procurement controls, detection through inspection and authentication techniques applied before components enter the system. AC-14 AC-20(5) CM-7(9) PL-8 PL-8(1) PM-30 PM-30(1) RA-3(1) SA-10(3) SA-10(4) SA-11 SA-3 SA-4(5) SA-8 SA-8(11) SA-8(13) SA-8(16) SA-9 SR-1 SR-10 SR-11 SR-11(3) SR-2 SR-2(1) SR-3 SR-4 SR-4(1) SR-4(2) SR-4(3) SR-4(4) SR-5 SR-5(2) SR-6(1) SR-9 SR-9(1) A.5.8 4.4 6.2 7.5.1 7.5.2 7.5.3 10.2 A.5.2 A.5.8 A.8.25 A.8.31 A.8.27 A.8.28 A.5.2 A.5.4 A.5.8 A.5.14 A.5.22 A.5.23 A.8.21 A.8.29 A.8.30 5.2 5.3 7.5.1 7.5.2 7.5.3 A.5.1 A.5.2 A.5.4 A.5.19 A.5.31 A.5.36 A.5.37 A.5.19 A.5.20 A.5.21 A.8.30 A.5.20 A.5.21 A.5.21 A.8.30 A.5.20 A.5.21 A.5.23 A.8.29
CM0025 Supplier Review A supplier review is a structured pre-contract assessment conducted before entering into any agreement with a contractor or subcontractor for the acquisition of systems, system components, or system services. The review evaluates the prospective supplier's security posture, trustworthiness, and capability to deliver components or services that meet the mission's integrity and assurance requirements, before contractual commitments are made and before the supplier gains access to mission information or influence over mission systems. Supplier reviews reduce the risk of introducing supply chain vulnerabilities through poorly qualified, compromised, or adversary-influenced suppliers at any tier of the acquisition chain. The rigor and depth of the review should be calibrated to the criticality of the components or services being acquired, with suppliers of mission-critical hardware, software, or services subject to the most intensive assessment. Supplier review findings should inform not only the decision to contract but also the specific security requirements, oversight provisions, and flow-down obligations included in the resulting agreement. PL-8 PL-8(1) PL-8(2) PM-30 PM-30(1) RA-3(1) SA-11 SA-11(3) SA-17 SA-2 SA-3 SA-8 SA-9 SR-11 SR-3(1) SR-3(3) SR-4 SR-4(1) SR-4(2) SR-4(3) SR-4(4) SR-5 SR-5(1) SR-5(2) SR-6 A.5.8 4.4 6.2 7.5.1 7.5.2 7.5.3 10.2 A.5.2 A.5.8 A.8.25 A.8.31 A.8.27 A.8.28 A.5.2 A.5.4 A.5.8 A.5.14 A.5.22 A.5.23 A.8.21 A.8.29 A.8.30 A.8.25 A.8.27 A.5.21 A.8.30 A.5.20 A.5.21 A.5.23 A.8.29 A.5.22
CM0027 ASIC/FPGA Manufacturing Custom application-specific integrated circuits (ASICs) should be fabricated through accredited trusted foundries, and field-programmable gate array (FPGA) devices should be procured through trusted suppliers with documented fabrication provenance, to reduce the risk of hardware Trojan insertion or unauthorized modification. Unlike software, hardware trojans embedded during semiconductor manufacturing are extremely difficult to detect through functional testing alone, as they may be designed to activate only under specific operational conditions or remain dormant indefinitely; the integrity of the fabrication source is therefore a primary defense. Trusted foundry accreditation provides assurance that the accredited fabrication activities are subject to security controls intended to reduce the risk of unauthorized modification. Assurance for design, intellectual property, aggregation, packaging, assembly, testing, and distribution must be addressed through trusted suppliers or other controls applicable to those lifecycle stages. This requirement applies to custom ASICs and to the base silicon used in FPGA implementations. The programmable design loaded onto an FPGA requires separate protection because trusted fabrication of the device does not establish the integrity or authenticity of the configured bitstream. AC-14 PL-8 PL-8(1) PL-8(2) PM-30 PM-30(1) RA-3(1) SA-10(3) SA-11 SA-3 SA-8 SA-8(11) SA-8(13) SA-8(16) SA-9 SI-3 SI-3(10) SR-1 SR-11 SR-2 SR-2(1) SR-3 SR-5 SR-5(2) SR-6(1) A.5.8 4.4 6.2 7.5.1 7.5.2 7.5.3 10.2 A.5.2 A.5.8 A.8.25 A.8.31 A.8.27 A.8.28 A.5.2 A.5.4 A.5.8 A.5.14 A.5.22 A.5.23 A.8.21 A.8.29 A.8.30 A.8.7 5.2 5.3 7.5.1 7.5.2 7.5.3 A.5.1 A.5.2 A.5.4 A.5.19 A.5.31 A.5.36 A.5.37 A.5.19 A.5.20 A.5.21 A.8.30 A.5.20 A.5.21 A.5.20 A.5.21 A.5.23 A.8.29
CM0028 Tamper Protection Tamper protection encompasses physical and logical controls that detect, deter, and respond to unauthorized modification of mission hardware and software throughout the acquisition, transit, storage, integration, and operational phases of the mission lifecycle. Physical tamper protection requires inspection of hardware at defined custody transfer points to detect evidence of unauthorized access or modification, and requires the use of tamper-evident packaging and sealing mechanisms during shipping and receiving to ensure that any interference with equipment in transit is detectable upon arrival. Logical tamper protection addresses the integrity of software and firmware through layered techniques including code obfuscation, integrity checks that verify software has not been altered from its approved state, and runtime integrity monitoring mechanisms such as self-checking code. Watchdog processes may supplement these controls by detecting abnormal execution or failure to complete expected processing, but do not by themselves verify software integrity. Physical and logical tamper protections are complementary and should be applied together where warranted by system criticality, threat exposure, and lifecycle conditions. Physical access to hardware can enable logical tampering, while failure to verify software integrity can reduce the assurance provided by physical controls. AC-14 AC-25 CA-8(1) CA-8(3) CM-7(9) MA-7 PL-8 PL-8(1) PL-8(2) PM-30 PM-30(1) RA-3(1) SA-10(3) SA-10(4) SA-11 SA-3 SA-4(5) SA-4(9) SA-8 SA-8(11) SA-8(13) SA-8(16) SA-8(19) SA-8(31) SA-9 SC-51 SR-1 SR-10 SR-11 SR-11(3) SR-2 SR-2(1) SR-3 SR-4(3) SR-4(4) SR-5 SR-5(2) SR-6(1) SR-9 SR-9(1) A.5.8 4.4 6.2 7.5.1 7.5.2 7.5.3 10.2 A.5.2 A.5.8 A.8.25 A.8.31 A.8.27 A.8.28 A.5.2 A.5.4 A.5.8 A.5.14 A.5.22 A.5.23 A.8.21 A.8.29 A.8.30 5.2 5.3 7.5.1 7.5.2 7.5.3 A.5.1 A.5.2 A.5.4 A.5.19 A.5.31 A.5.36 A.5.37 A.5.19 A.5.20 A.5.21 A.8.30 A.5.20 A.5.21 A.5.20 A.5.21 A.5.23 A.8.29
CM0021 Software Digital Signature Each software or firmware image subject to installation or update control shall be verified using an approved digital signature and an approved trust anchor before installation or activation. The trust anchor may be represented by a certificate or by a directly provisioned verification key, depending on the approved trust architecture. Successful verification establishes that the image was signed by an authorized signing identity and has not been modified since signing; it does not establish that the signed code is non-malicious, vulnerability-free, or operationally safe. Signature verification confirms the integrity and approved origin of the software but does not, by itself, prevent installation of an older validly signed version; update authorization and rollback protections must be enforced separately. The verification mechanism must be implemented such that it cannot be bypassed through operational commands, configuration changes, or software updates, and must reject any component whose signature is absent or invalid, or whose signing certificate or trust anchor is not recognized and approved by the mission. Digital signature enforcement complements but is distinct from the boot-time chain of trust established through secure boot; it applies to software installation and update events throughout the operational lifecycle, not only at system startup. AC-14 CM-11 CM-11(3) CM-14 CM-5(6) IA-2 SA-10(1) SA-11 SA-4(5) SA-8(29) SA-8(31) SA-9 SI-7 SI-7(1) SI-7(12) SI-7(15) SI-7(6) A.8.19 A.5.16 A.5.2 A.5.4 A.5.8 A.5.14 A.5.22 A.5.23 A.8.21 A.8.29 A.8.30
CM0068 Reinforcement Learning A reinforcement learning (RL) agent deployed within the spacecraft or ground system can provide an adaptive, autonomous anomaly detection and response capability that identifies anomalous events, including malicious data inputs and injected commands, and redirects affected processes to proceed safely by ignoring or isolating the malicious input. An RL agent learns a response policy that maps observations to actions according to its training environment and reward function. It may generalize to scenarios not explicitly included in training, but its ability to detect or respond correctly to novel attacks or conditions outside the validated operational envelope must not be assumed. Anomaly detection may be incorporated into the RL architecture or provided by a separate monitoring function. Effective deployment requires separate protections against compromise of the training process and manipulation of observations presented to the deployed agent. Online learning or policy adaptation should be disabled unless specifically authorized, bounded, and validated. Agent-selected responses must be constrained by a trusted safety mechanism. IR-5 IR-5(1) SI-4 SI-4(2) A.8.16
CM0014 Secure boot Secure boot establishes and enforces a cryptographically verified chain of trust from a hardware-anchored root of trust (RoT) through each applicable stage of the startup sequence to the operating system or flight software image. Each stage in the chain must verify the integrity and authenticity of the next before transferring execution control. The boot policy must also prevent execution of unauthorized or revoked images, including unauthorized rollback to an older but validly signed software version. The trust anchor and initial verification function should be immutable after provisioning or protected by hardware-enforced mechanisms that prevent unauthorized modification and preserve their integrity. Components implementing the RoT must also be qualified for the expected mission radiation environment. Radiation tolerance addresses the reliability of the trust anchor, while immutability or protected update mechanisms address its resistance to unauthorized modification. This is particularly critical where radiation-induced bit flips and the physical inaccessibility of on-orbit hardware make a tamper-resistant, immutable hardware anchor essential to sustained boot integrity across the mission lifetime. AC-14 PL-8 PL-8(1) SA-8(10) SA-8(12) SA-8(13) SA-8(3) SA-8(30) SA-8(4) SC-51 SI-7 SI-7(1) SI-7(10) SI-7(9) A.5.8