Detects rollback in GNSS time sensor readings compared to an external or independently maintained timestamp. The GNSS-reported time is older than previously recorded values, suggesting potential spoofing, recovery from interference, or malicious time manipulation. A GNSS time rewind event was flagged based on observed time discontinuity. Requires logic outside STIX to compute and set rewind_detected.
| ID | Name | Description | |
| EX-0014 | Spoofing | The adversary forges inputs that subsystems treat as trustworthy truth, time tags, sensor measurements, bus messages, or navigation signals, so onboard logic acts on fabricated reality. Because many control loops and autonomy rules assume data authenticity once it passes basic sanity checks, carefully shaped spoofs can trigger mode transitions, safing, actuator commands, or payload behaviors without touching flight code. Spoofing may occur over RF (e.g., GNSS, crosslinks, TT&C beacons), over internal networks/buses (message injection with valid identifiers), or at sensor/actuator interfaces (electrical/optical stimulation that produces plausible readings). Effects range from subtle bias (drifting estimates, skewed calibrations) to acute events (unexpected slews, power reconfiguration, recorder re-indexing), and can also pollute downlinked telemetry or science products so ground controllers interpret a false narrative. The hallmark is that the spacecraft chooses the adversary’s action path because the forged data passes through normal processing chains. | |
| EX-0014.01 | Time Spoof | Time underpins sequencing, anti-replay, navigation filtering, and data labeling. An attacker that forges or biases the time seen by onboard consumers can reorder stored command execution, break timetag validation, desynchronize counters, and misalign estimation windows. Spoofing vectors include manipulating the distributed time service, introducing a higher-priority/cleaner time source (e.g., GNSS-derived time), or crafting messages that cause clock discipline to slew toward attacker-chosen values. Once time shifts, autonomous routines keyed to epochs, wheel unloads, downlink starts, heater schedules, fire early/late or not at all, and telemetry appears inconsistent to ground analysis. The signature is correct-looking time metadata that steadily or abruptly departs from truth, driving downstream logic to act at the wrong moment. | |
| EX-0014.04 | Position, Navigation, and Timing (PNT) Spoofing | The adversary transmits GNSS-like signals (or manipulates crosslink-distributed time/ephemeris) so the spacecraft’s navigation solution reflects attacker-chosen states. With believable code phases, Doppler, and navigation messages, the victim can be pulled to a false position/velocity/time, causing downstream functions, attitude pointing limits, station visibility prediction, eclipse timing, antenna pointing, and anti-replay windows, to misbehave. Even when GNSS is not the primary navigation source, spoofed PNT can bias timekeeping or seed filters that fuse multiple sensors, leading to mis-scheduling and errant control. The defining feature is externally provided navigation/time that passes validity checks yet encodes a crafted trajectory or epoch. | |