Monitors for excessive access to critical memory regions, which may indicate malicious activities. On a spacecraft, consistent and unexpected access (read or write) to critical memory regions could indicate malicious activities by malware.

STIX Pattern

[x-opencti-memory:access_frequency > 'expected_rate' AND x-opencti-memory:memory_region != 'expected']

SPARTA TTPs

ID	Name	Description
EX-0004	Compromise Boot Memory	Threat actors may manipulate boot memory in order to execute malicious code, bypass internal processes, or DoS the system. This technique can be used to perform other tactics such as Defense Evasion.
EX-0005	Exploit Hardware/Firmware Corruption	Threat actors can target the underlying hardware and/or firmware using various TTPs that will be dependent on the specific hardware/firmware. Typically, software tools (e.g., antivirus, antimalware, intrusion detection) can protect a system from threat actors attempting to take advantage of those vulnerabilities to inject malicious code. However, there exist security gaps that cannot be closed by the above-mentioned software tools since they are not stationed on software applications, drivers or the operating system but rather on the hardware itself. Hardware components, like memory modules and caches, can be exploited under specific circumstances thus enabling backdoor access to potential threat actors. In addition to hardware, the firmware itself which often is thought to be software in its own right also provides an attack surface for threat actors. Firmware is programming that's written to a hardware device's non-volatile memory where the content is saved when a hardware device is turned off or loses its external power source. Firmware is written directly onto a piece of hardware during manufacturing and it is used to run on the device and can be thought of as the software that enables hardware to run. In the spacecraft context, firmware and field programmable gate array (FPGA)/application-specific integrated circuit (ASIC) logic/code is considered equivalent to firmware.
EX-0005.01	Design Flaws	Threat actors may target design features/flaws with the hardware design to their advantage to cause the desired impact. Threat actors may utilize the inherent design of the hardware (e.g. hardware timers, hardware interrupts, memory cells), which is intended to provide reliability, to their advantage to degrade other aspects like availability. Additionally, field programmable gate array (FPGA)/application-specific integrated circuit (ASIC) logic can be exploited just like software code can be exploited. There could be logic/design flaws embedded in the hardware (i.e., FPGA/ASIC) which may be exploitable by a threat actor.
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-0012.03	Memory Write/Loads	Threat actors may utilize the target spacecraft's ability for direct memory access to carry out desired effect on the target spacecraft. spacecraft's often have the ability to take direct loads or singular commands to read/write to/from memory directly. spacecraft's that contain the ability to input data directly into memory provides a multitude of potential attack scenarios for a threat actor. Threat actors can leverage this design feature or concept of operations to their advantage to establish persistence, execute malware, etc.
EX-0012.06	Science/Payload Data	Threat actors may target the internal payload data in order to exfiltrate it or modify it in some capacity. Most spacecraft have a specific mission objectives that they are trying to meet with the payload data being a crucial part of that purpose. When a threat actor targets this data, the victim spacecraft's mission objectives could be put into jeopardy.
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.
EX-0014.01	Time Spoof	Threat actors may attempt to target the internal timers onboard the victim spacecraft and spoof their data. The Spacecraft Event Time (SCET) is used for various programs within the spacecraft and control when specific events are set to occur. Ground controllers use these timed events to perform automated processes as the spacecraft is in orbit in order for it to fulfill it's purpose. Threat actors that target this particular system and attempt to spoof it's data could cause these processes to trigger early or late.
EX-0014.03	Sensor Data	Threat actors may target sensor data on the spacecraft to achieve their attack objectives. Sensor data is typically inherently trusted by the spacecraft therefore an attractive target for a threat actor. Spoofing the sensor data could affect the calculations and disrupt portions of a control loop as well as create uncertainty within the mission thereby creating temporary denial of service conditions for the mission. Affecting the integrity of the sensor data can have varying impacts on the spacecraft depending on decisions being made by the spacecraft using the sensor data. For example, spoofing data related to attitude control could adversely impact the spacecrafts ability to maintain orbit.
PER-0001	Memory Compromise	Threat actors may manipulate memory (boot, RAM, etc.) in order for their malicious code and/or commands to remain on the victim spacecraft. The spacecraft may have mechanisms that allow for the automatic running of programs on system reboot, entering or returning to/from safe mode, or during specific events. Threat actors may target these specific memory locations in order to store their malicious code or file, ensuring that the attack remains on the system even after a reset.