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	Inject Malicious Code	Threat actors may rely on other tactics and techniques in order to inject malicious code into 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 may take advantage of the victim spacecraft being in safe mode and send malicious commands that may not otherwise be processed. Safe-mode is when all non-essential systems are shut down and only essential functions within the spacecraft are active. During this mode, several commands are available to be processed that are not normally processed. Further, many protections may be disabled at this time.
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	Prevent Downlink	Threat actors may target the downlink connections to prevent the victim spacecraft from sending telemetry to the ground controllers. 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.
DE-0002.01	Inhibit Ground System Functionality	Threat actors may utilize ground-system presence to inhibit the ground system software's ability to process (or display) telemetry, 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.
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 Intercept	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.