Monitor Critical Telemetry Points

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.

Best Segment for Countermeasure Deployment

  • Ground Segment

NIST Rev5 Controls

D3FEND

ISO 27001

ID: CM0034
ESA Space Shield Mitigation:  M2076 | M2017
Created: 2022/10/19
Last Modified: 2023/11/29

Techniques Addressed by Countermeasure

ID Name Description
IA-0003 Crosslink via Compromised Neighbor Threat actors may compromise a victim spacecraft via the crosslink communications of a neighboring spacecraft that has been compromised. spacecraft in close proximity are able to send commands back and forth. Threat actors may be able to leverage this access to compromise other spacecraft once they have access to another that is nearby.
IA-0007 Compromise Ground System Threat actors may initially compromise the ground system in order to access the target spacecraft. Once compromised, the threat actor can perform a multitude of initial access techniques, including replay, compromising FSW deployment, compromising encryption keys, and compromising authentication schemes. Threat actors may also perform further reconnaissance within the system to enumerate mission networks and gather information related to ground station logical topology, missions ran out of said ground station, birds that are in-band of targeted ground stations, and other mission system capabilities.
.01 Compromise On-Orbit Update Threat actors may manipulate and modify on-orbit updates before they are sent to the target spacecraft. This attack can be done in a number of ways, including manipulation of source code, manipulating environment variables, on-board table/memory values, or replacing compiled versions with a malicious one.
.02 Malicious Commanding via Valid GS Threat actors may compromise target owned ground systems components (e.g., front end processors, command and control software, etc.) that can be used for future campaigns or to perpetuate other techniques. These ground systems components have already been configured for communications to the victim spacecraft. By compromising this infrastructure, threat actors can stage, launch, and execute an operation. Threat actors may utilize these systems for various tasks, including Execution and Exfiltration.
IA-0008 Rogue External Entity Threat actors may gain access to a victim spacecraft through the use of a rogue external entity. With this technique, the threat actor does not need access to a legitimate ground station or communication site.
.01 Rogue Ground Station Threat actors may gain access to a victim spacecraft through the use of a rogue ground system. With this technique, the threat actor does not need access to a legitimate ground station or communication site.
.02 Rogue Spacecraft Threat actors may gain access to a target spacecraft using their own spacecraft that has the capability to maneuver within close proximity to a target spacecraft to carry out a variety of TTPs (i.e., eavesdropping, side-channel, etc.). Since many of the commercial and military assets in space are tracked, and that information is publicly available, attackers can identify the location of space assets to infer the best positioning for intersecting orbits. Proximity operations support avoidance of the larger attenuation that would otherwise affect the signal when propagating long distances, or environmental circumstances that may present interference.
IA-0009 Trusted Relationship Access through trusted third-party relationship exploits an existing connection that has been approved for interconnection. Leveraging third party / approved interconnections to pivot into the target systems is a common technique for threat actors as these interconnections typically lack stringent access control due to the trusted status.
.02 Vendor Threat actors may target the trust between vendors and the target space vehicle. Missions often grant elevated access to vendors in order to allow them to manage internal systems as well as cloud-based environments. The vendor's access may be intended to be limited to the infrastructure being maintained but it may provide laterally movement into the target space vehicle. Attackers may leverage security weaknesses in the vendor environment to gain access to more critical mission resources or network locations. In the space vehicle context vendors may have direct commanding and updating capabilities outside of the primary communication channel.
EX-0001 Replay Replay attacks involve threat actors recording previously recorded data streams and then resending them at a later time. This attack can be used to fingerprint systems, gain elevated privileges, or even cause a denial of service.
.01 Command Packets Threat actors may interact with the victim spacecraft by replaying captured commands to the spacecraft. While not necessarily malicious in nature, replayed commands can be used to overload the target spacecraft and cause it's onboard systems to crash, perform a DoS attack, or monitor various responses by the spacecraft. If critical commands are captured and replayed, thruster fires, then the impact could impact the spacecraft's attitude control/orbit.
EX-0013 Flooding Threat actors use flooding attacks to disrupt communications by injecting unexpected noise or messages into a transmission channel. There are several types of attacks that are consistent with this method of exploitation, and they can produce various outcomes. Although, the most prominent of the impacts are denial of service or data corruption. Several elements of the space vehicle may be targeted by jamming and flooding attacks, and depending on the time of the attack, it can have devastating results to the availability of the system.
.01 Valid Commands Threat actors may utilize valid commanding as a mechanism for flooding as the processing of these valid commands could expend valuable resources like processing power and battery usage. Flooding the spacecraft bus, sub-systems or link layer with valid commands can create temporary denial of service conditions for the space vehicle while the spacecraft is consumed with processing these valid commands.
.02 Erroneous Input Threat actors inject noise/data/signals into the target channel so that legitimate messages cannot be correctly processed due to impacts to integrity or availability. Additionally, while this technique does not utilize system-relevant signals/commands/information, the target spacecraft may still consume valuable computing resources to process and discard the signal.
EX-0016 Jamming Threat actors may attempt to jam Global Navigation Satellite Systems (GNSS) signals (i.e. GPS, Galileo, etc.) to inhibit a spacecraft's position, navigation, and/or timing functions.
.03 Position, Navigation, and Timing (PNT) Threat actors may attempt to jam Global Navigation Satellite Systems (GNSS) signals (i.e. GPS, Galileo, etc.) to inhibit a spacecraft's position, navigation, and/or timing functions.
PER-0003 Ground System Presence Threat actors may compromise target owned ground systems that can be used for persistent access to the spacecraft or to perpetuate other techniques. These ground systems have already been configured for communications to the victim spacecraft. By compromising this infrastructure, threat actors can stage, launch, and execute persistently.
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.
.02 Jam Link Signal Threat actors may overwhelm/jam the downlink signal to prevent transmitted telemetry signals from reaching their destination without severe modification/interference, 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-0003 Modify On-Board Values Threat actors may target various onboard values put in place to prevent malicious or poorly crafted commands from being processed. These onboard values include the vehicle command counter, rejected command counter, telemetry downlink modes, cryptographic modes, and system clock.
.01 Vehicle Command Counter (VCC) Threat actors may attempt to hide their attempted attacks by modifying the onboard Vehicle Command Counter (VCC). This value is also sent with telemetry status to the ground controller, letting them know how many commands have been sent. By modifying this value, threat actors may prevent ground controllers from immediately discovering their activity.
.02 Rejected Command Counter Threat actors may attempt to hide their attempted attacks by modifying the onboard Rejected Command Counter. Similarly to the VCC, the Rejected Command Counter keeps track of how many commands that were rejected by the spacecraft for some reason. Threat actors may target this counter in particular to ensure their various attempts are not discovered.
.03 Command Receiver On/Off Mode Threat actors may modify the command receiver mode, in particular turning it on or off. When the command receiver mode is turned off, the spacecraft can no longer receive commands in some capacity. Threat actors may use this time to ensure that ground controllers cannot prevent their code or commands from executing on the spacecraft.
.04 Command Receivers Received Signal Strength Threat actors may target the on-board command receivers received signal parameters (i.e., automatic gain control (AGC)) in order to stop specific commands or signals from being processed by the spacecraft. For ground controllers to communicate with spacecraft in orbit, the on-board receivers need to be configured to receive signals with a specific signal to noise ratio (ratio of signal power to the noise power). Targeting values related to the antenna signaling that are modifiable can prevent the spacecraft from receiving ground commands.
.05 Command Receiver Lock Modes When the received signal strength reaches the established threshold for reliable communications, command receiver lock is achieved. Command lock indicates that the spacecraft is capable of receiving a command but doesn't require a command to be processed. Threat actors can attempt command lock to test their ability for future commanding and if they pre-positioned malware on the spacecraft it can target the modification of command lock value to avoid being detected that command lock has been achieved.
.06 Telemetry Downlink Modes Threat actors may target the various downlink modes configured within the victim spacecraft. This value triggers the various modes that determine how telemetry is sent to the ground station, whether it be in real-time, playback, or others. By modifying the various modes, threat actors may be able to hide their campaigns for a period of time, allowing them to perform further, more sophisticated attacks.
.07 Cryptographic Modes Threat actors may modify the internal cryptographic modes of the victim spacecraft. Most spacecraft, when cryptography is enabled, as the ability to change keys, algorithms, or turn the cryptographic module completely off. Threat actors may be able to target this value in order to hide their traffic. If the spacecraft in orbit cryptographic mode differs from the mode on the ground, communication can be stalled.
.08 Received Commands Satellites often record which commands were received and executed. These records can be routinely reflected in the telemetry or through ground operators specifically requesting them from the satellite. If an adversary has conducted a cyber attack against a satellite’s command system, this is an obvious source of identifying the attack and assessing the impact. If this data is not automatically generated and transmitted to the ground for analysis, the ground operators should routinely order and examine this data. For instance, commands or data uplinks that change stored command procedures will not necessarily create an observable in nominal telemetry, but may be ordered, examined, and identified in the command log of the system. Threat actors may manipulate these stored logs to avoid detection.
.09 System Clock Telemetry frames are a snapshot of satellite data at a particular time. Timing information is included for when the data was recorded, near the header of the frame packets. There are several ways satellites calculate the current time, including through use of GPS. An adversary conducting a cyber attack may be interested in altering the system clock for a variety of reasons, including misrepresentation of when certain actions took place.
.10 GPS Ephemeris A satellite with a GPS receiver can use ephemeris data from GPS satellites to estimate its own position in space. A hostile actor could spoof the GPS signals to cause erroneous calculations of the satellite’s position. The received ephemeris data is often telemetered and can be monitored for indications of GPS spoofing. Reception of ephemeris data that changes suddenly without a reasonable explanation (such as a known GPS satellite handoff), could provide an indication of GPS spoofing and warrant further analysis. Threat actors could also change the course of the vehicle and falsify the telemetered data to temporarily convince ground operators the vehicle is still on a proper course.
.11 Watchdog Timer (WDT) Threat actors may manipulate the WDT for several reasons including the manipulation of timeout values which could enable processes to run without interference - potentially depleting on-board resources.
DE-0004 Masquerading Threat actors may gain access to a victim spacecraft by masquerading as an authorized entity. This can be done several ways, including through the manipulation of command headers, spoofing locations, or even leveraging Insider's access (i.e., Insider Threat)
DE-0010 Overflow Audit Log Threat actors may seek to exploit the inherent nature of flight software and its limited capacity for event logging/storage between downlink windows as a means to conceal malicious activity.
LM-0003 Constellation Hopping via Crosslink Threat actors may attempt to command another neighboring spacecraft via crosslink. spacecraft in close proximity are often able to send commands back and forth. Threat actors may be able to leverage this access to compromise another spacecraft.
EXF-0001 Replay Threat actors may exfiltrate data by replaying commands and capturing the telemetry or payload data as it is sent down. One scenario would be the threat actor replays commands to downlink payload data once the spacecraft is within certain location so the data can be intercepted on the downlink by threat actor ground terminals.

Space Threats Addressed by Countermeasure

ID Description
SV-IT-5 Onboard control procedures (i.e., ATS/RTS) that execute a scripts/sets of commands  
SV-AV-5 Using fault management system against you. Understanding the fault response could be leveraged to get satellite in vulnerable state. Example, safe mode with crypto bypass, orbit correction maneuvers, affecting integrity of TLM to cause action from ground, or some sort of RPO to cause S/C to go into safe mode;  
SV-DCO-1 Not knowing that you were attacked, or attack was attempted  
SV-AC-1 Attempting access to an access-controlled system resulting in unauthorized access  
SV-AC-2 Replay of recorded authentic communications traffic at a later time with the hope that the authorized communications will provide data or some other system reaction  
SV-CF-1 Tapping of communications links (wireline, RF, network) resulting in loss of confidentiality; Traffic analysis to determine which entities are communicating with each other without being able to read the communicated information  
SV-IT-1 Communications system spoofing resulting in denial of service and loss of availability and data integrity  
SV-AV-1 Communications system jamming resulting in denial of service and loss of availability and data integrity