Detection of an unexpected modification in the memory block associated with telemetry data. The system identifies abnormal write operations in memory locations that store telemetry information before it is transmitted, suggesting manipulation by malware. Adversaries may change telemetry before downlink in order to prevent the ground from being aware of malware being on the spacecraft.

STIX Pattern

[x-opencti-memory:block = 'telemetry_memory_block' AND x-opencti-memory:write_operation = 'unexpected' AND x-opencti-memory:modification_time != 'authorized_time']

SPARTA TTPs

ID	Name	Description
EX-0010	Malicious Code	Threat actors may rely on other tactics and techniques in order to execute malicious code on the victim spacecraft. This can be done via compromising the supply chain or development environment in some capacity or taking advantage of known commands. However, once malicious code has been uploaded to the victim spacecraft, the threat actor can then trigger the code to run via a specific command or wait for a legitimate user to trigger it accidently. The code itself can do a number of different things to the hosted payload, subsystems, or underlying OS.
EX-0011	Exploit Reduced Protections During Safe-Mode	Threat actors who have access to a spacecraft in safe mode may issue malicious commands that would not normally be accepted during nominal operations. Safe-mode is when all non-essential systems are shut down and only essential functions within the spacecraft are active. Because safe mode prioritizes essential functions and often disables non-critical protections or filters, adversaries can exploit this state to trigger unauthorized reconfiguration, software modification, or system manipulation during recovery or degraded operation.
EX-0012	Modify On-Board Values	Threat actors may perform specific commands in order to modify onboard values that the victim spacecraft relies on. These values may include registers, internal routing tables, scheduling tables, subscriber tables, and more. Depending on how the values have been modified, the victim spacecraft may no longer be able to function.
EX-0014	Spoofing	Threat actors may attempt to spoof the various sensor and controller data that is depended upon by various subsystems within the victim spacecraft. Subsystems rely on this data to perform automated tasks, process gather data, and return important information to the ground controllers. By spoofing this information, threat actors could trigger automated tasks to fire when they are not needed to, potentially causing the spacecraft to behave erratically. Further, the data could be processed erroneously, causing ground controllers to receive incorrect telemetry or scientific data, threatening the spacecraft's reliability and integrity.
DE-0002	Disrupt or Deceive Downlink	Threat actors may target ground-side telemetry reception, processing, or display to disrupt the operator’s visibility into spacecraft health and activity. This may involve denial-based attacks that prevent the spacecraft from transmitting telemetry to the ground (e.g., disabling telemetry links or crashing telemetry software), or more subtle deception-based attacks that manipulate telemetry content to conceal unauthorized actions. Since telemetry is the primary method ground controllers rely on to monitor spacecraft status, any disruption or manipulation can delay or prevent detection of malicious activity, suppress automated or manual mitigations, or degrade trust in telemetry-based decision support systems.
DE-0002.01	Inhibit Ground System Functionality	Threat actors may utilize access to the ground system to inhibit its ability to accurately process, render, or interpret spacecraft telemetry, effectively leaving ground controllers unaware of the spacecraft’s true state or activity. This may involve traditional denial-based techniques, such as disabling telemetry software, corrupting processing pipelines, or crashing display interfaces. In addition, more subtle deception-based techniques may be used to falsify telemetry data within the ground system — such as modifying command counters, acknowledgments, housekeeping data, or sensor outputs — to provide the appearance of nominal operation. These actions can suppress alerts, mask unauthorized activity, or prevent both automated and manual mitigations from being initiated based on misleading ground-side information. Because telemetry is the primary method by which ground controllers monitor the health, behavior, and safety of the spacecraft, any disruption or falsification of this data directly undermines situational awareness and operational control.
DE-0002.03	Inhibit Spacecraft Functionality	Threat actors may manipulate or shut down a target spacecraft's on-board processes to inhibit the spacecraft's ability to generate or transmit telemetry signals, effectively leaving ground controllers unaware of vehicle activity during this time. Telemetry is the only method in which ground controllers can monitor the health and stability of the spacecraft while in orbit. By disabling this downlink, threat actors may be able to stop mitigations from taking place.
EXF-0003.02	Downlink Exfiltration	Threat actors may target the downlink connection from the victim spacecraft in order to exfiltrate telemetry or payload data. This data can include health information of the spacecraft or mission data that is being collected/analyzed on the spacecraft. Downlinked data can even include mirrored command sessions which can be used for future campaigns or to help perpetuate other techniques.