Monitors the cryptographic integrity of data (files, payload data, configuration file, logs, etc.) to ensure it remains unmodified during data storage or transmission. It is important during engineering to determine the critical data items that need integrity protection. Some example are discussed in evasion technique https://sparta.aerospace.org/technique/DE-0003/
| ID | Name | Description | |
| IA-0001.02 | Software Supply Chain | Here the manipulation targets software delivered to flight or ground systems: altering source before build, swapping signed binaries at distribution edges, subverting update metadata, or using stolen signing keys to issue malicious patches. Space-specific vectors include mission control applications, schedulers, gateway services, flight tables and configuration packages, and firmware loads during I&T or LEOP. Adversaries craft payloads that pass superficial validation, trigger under particular operating modes, or reintroduce known weaknesses through version rollback. “Data payloads” such as malformed tables, ephemerides, or calibration products can double as exploits when parsers are permissive. The objective is to ride the normal promotion pipeline so the implant arrives pre-trusted and executes as part of routine operations. | |
| IA-0007.01 | Compromise On-Orbit Update | Adversaries may target the pipeline that produces and transmits updates to an on-orbit vehicle. Manipulation points include source repositories and configuration tables, build and packaging steps that generate images or differential patches, staging areas on ground servers, update metadata (versions, counters, manifests), and the transmission process itself. Spacecraft updates span flight software patches, FPGA bitstreams, bootloader or device firmware loads, and operational data products such as command tables, ephemerides, and calibration files, each with distinct formats, framing, and acceptance rules. An attacker positioned in the ground system can substitute or modify an artifact, alter its timing and timetags to match pass windows, and queue it through the same procedures operators use for nominal maintenance. Activation can be immediate or deferred: implants may lie dormant until a specific mode, safing entry, or table index is referenced. | |
| EX-0010 | Malicious Code | The adversary achieves on-board effects by introducing executable logic that runs on the vehicle, either native binaries and scripts, injected shellcode, or “data payloads” that an interpreter treats as code (e.g., procedure languages, table-driven automations). Delivery commonly piggybacks on legitimate pathways: software/firmware updates, file transfer services, table loaders, maintenance consoles, or command sequences that write to executable regions. Once staged, activation can be explicit (a specific command, mode change, or file open), environmental (time/geometry triggers), or accidental, where operator actions or routine autonomy invoke the implanted logic. Malicious code can target any layer it can reach: altering flight software behavior, manipulating payload controllers, patching boot or device firmware, or installing hooks in drivers and gateways that bridge bus and payload traffic. Effects range from subtle logic changes (quiet data tampering, command filtering) to overt actions (forced mode transitions, resource starvation), and may include secondary capabilities like covert communications, key material harvesting, or persistence across resets by rewriting images or configuration entries. | |
| EX-0010.03 | Rootkit | A rootkit hides the presence and activity of other malicious components by interposing on the mechanisms that report system state. On spacecraft this can occur within flight software processes, at OS kernel level, inside separation kernels/hypervisors, or down in system firmware where drivers and initialization routines run. Techniques include API and syscall hooking, patching message queues and inter-process communication paths, altering task lists and scheduler views, filtering telemetry packets and event logs, and rewriting sensor or health values before they are recorded or downlinked. Rootkits may also hook command handlers and gateways so certain opcodes, timetags, or sources are silently accepted or ignored while external observers see normal acknowledgments. Because many missions rely on deterministic procedures and limited observability, even small alterations to reporting can make malicious actions appear as plausible mode transitions or benign anomalies. Persistence often pairs with the concealment layer, with the rootkit reinjecting companions after resets or rebuilds by monitoring for specific files, tables, or image loads and modifying them on the fly. | |
| EX-0010.04 | Bootkit | A bootkit positions itself in the pre-OS boot chain so that it executes before normal integrity checks and can shape what the system subsequently trusts. After seizing early control, the bootkit can redirect image selection, patch kernels or flight binaries in memory, adjust device trees and driver tables, or install hooks that persist across warm resets. Some variants maintain shadow copies of legitimate images and present them to basic verification routines while steering actual execution to a modified payload; others manipulate fallback logic so recovery modes load attacker-controlled code. Because the boot path initializes memory maps, buses, and authentication material, a bootkit can also influence key/counter setup and gateway configurations, creating conditions favorable to later tactics. The central characteristic is precedence: by running first, the implant defines the reality higher layers observe, ensuring that every subsequent component launches under conditions curated by the attacker. | |
| EX-0012.02 | Internal Routing Tables | Threat actors may rewrite the maps that tell software where to send and receive things. In publish/subscribe or message-queued flight frameworks, tables map message IDs to subscribers, opcodes to handlers, and pipes to processes; at interfaces, address/port maps define how traffic traverses bridges and gateways (e.g., SpaceWire node/port routes, 1553 RT/subaddress mappings, CAN IDs). By altering these structures, commands can be misdelivered, dropped, duplicated, or routed through unintended paths; telemetry can be redirected or blackholed; and handler bindings can be swapped so an opcode triggers the wrong function. Schedule/routing hybrids, used to sequence activities and distribute results, can be edited to reorder execution or to create feedback loops that occupy bandwidth and processor time. The result is control over who hears what and when, achieved by changing the lookup tables that underpin command/telemetry distribution rather than the code that processes them. | |
| EX-0012.04 | App/Subscriber Tables | In publish/subscribe flight frameworks, applications and subsystems register interest in specific message classes via subscriber (or application) tables. These tables map message IDs/topics to subscribers, define delivery pipes/queues, and often include filters, priorities, and rate limits. By altering these mappings, an adversary can quietly reshape information flow: critical consumers stop receiving health or sensor messages; non-critical tasks get flooded; handlers are rebound so an opcode or message ID reaches the wrong task; or duplicates create feedback loops that consume bandwidth and CPU. Because subscription state is usually read at init or refreshed on command, subtle edits can persist across reboots or take effect at predictable times. Similar effects appear in legacy MIL-STD-1553 deployments by modifying Remote Terminal (RT), subaddress, or mode-code configurations so that messages are misaddressed or dropped at the bus interface. The net result is control-by-misdirection: the software still “works,” but the right data no longer reaches the right recipient at the right time. | |
| EX-0012.05 | Scheduling Algorithm | Spacecraft typically rely on real-time scheduling, fixed-priority or deadline/periodic schemes, driven by timers, tick sources, and per-task parameters. Threat actors target these parameters and associated tables to skew execution order and timing. Edits may change priorities, periods, or deadlines; adjust CPU budgets and watchdog thresholds; alter ready-queue disciplines; or reconfigure timer tick rates and clock sources. They may also modify task affinities, message-queue depths, and interrupt masks so preemption and latency characteristics shift. Small changes can have large effects: high-rate control loops see added jitter, estimator updates miss deadlines, command/telemetry handling starves, or low-priority maintenance tasks monopolize cores due to mis-set periods. Manipulated schedules can create intermittent, state-dependent malfunctions that are hard to distinguish from environmental load. The essence of the technique is to weaponize time, reshaping when work happens so that otherwise correct code produces unsafe or exploitable behavior. | |
| EX-0012.06 | Science/Payload Data | Payload data, and the metadata that gives it meaning, can be altered in place to steal value, mislead users, or degrade mission outputs. Targets include raw detector frames, packetized Level-0 streams, onboard preprocessed products, and file catalogs/directories on mass memory. Adjacent metadata such as timestamps, pointing/attitude tags, calibration coefficients, compression settings, and quality flags are equally potent; slight bias in a calibration table or time tag can skew entire downlink campaigns while appearing routine. An adversary may rewrite frame headers, reorder packets, substitute segments from prior passes, or flip quality bits so ground pipelines silently discard or misclassify products. Recorder index manipulation can orphan files or cause downlinks to serve stale or fabricated content. Because many missions perform some processing or filtering onboard, tampering upstream of downlink propagates forward as “authoritative” truth, jeopardizing mission objectives without obvious protocol anomalies. | |
| PER-0004 | Replace Cryptographic Keys | The adversary cements control by changing the cryptographic material the spacecraft uses to authenticate or protect links and updates. Targets include uplink authentication keys and counters, link-encryption/session keys and key-encryption keys (KEKs), key identifiers/selectors, and algorithm profiles. Using authorized rekey commands or key-loading procedures, often designed for over-the-air use, the attacker installs new values in non-volatile storage and updates selectors so subsequent traffic must use the attacker’s keys to be accepted. Variants desynchronize anti-replay by advancing counters or switching epochs, or strand operators by flipping profiles to a mode for which only the adversary holds parameters. Once replaced, the new material persists across resets and mode changes, turning the spacecraft into a node that recognizes the adversary’s channel while rejecting former controllers. | |
| DE-0003.01 | Vehicle Command Counter (VCC) | The VCC tracks how many commands the spacecraft has accepted. An adversary masks activity by zeroing, freezing, or selectively decrementing the VCC, or by steering actions through paths that do not increment it (maintenance dictionaries, alternate receivers, hidden handlers). They may also overwrite the telemetry field that reports the VCC so ground displays show a lower or steady count while high volumes of commands are processed. This breaks simple “command volume” heuristics and makes bursty activity look normal. | |
| DE-0003.02 | Rejected Command Counter | This counter records commands that failed checks or were refused. To hide probing and trial-and-error, the adversary suppresses increments, periodically clears the value, or forges the downlinked field so rejection rates appear benign. Variants also tamper with associated reason codes or event entries, replacing them with innocuous outcomes. Analysts reviewing telemetry see no evidence of failed attempts even as the system is being exercised aggressively. | |
| DE-0003.03 | Command Receiver On/Off Mode | By toggling receiver enable states (per-receiver, per-antenna, or per-band), the adversary creates deliberate “quiet windows” in which outside intervention cannot arrive. Turning a command receiver off, or shifting to a configuration that ignores the primary path, allows queued actions or onboard procedures to run without interruption, while operators perceive a transient loss of commandability consistent with geometry or environment. Brief, well-timed toggles can also desynchronize counters and handovers, complicating reconstruction of what occurred. | |
| DE-0003.04 | 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. | |
| DE-0003.05 | Command Receiver Lock Modes | Receivers advertise acquisition states, bit lock, frame lock, and command lock, that indicate readiness to accept telecommands. Adversaries leverage these indicators in two ways: (1) use command-lock tests to validate geometry, power, Doppler, and polarization without risking visible command execution; and (2) tamper with the values that report lock status so ground views never show that lock was achieved. Techniques include freezing or clearing lock flags and counters, raising/lowering internal thresholds so lock occurs without being reported (or vice versa), and timing brief lock intervals between telemetry samples. The result is a window where the spacecraft is receptive to commands while downlinked status suggests otherwise. | |
| DE-0003.06 | Telemetry Downlink Modes | Spacecraft expose modes that control what telemetry is sent and how, real-time channels, recorder playback, beacon/summary only, event-driven reporting, and per-virtual-channel/APID selections. By switching modes or editing the associated parameters (rates, filters, playback queues, index ranges), an adversary can thin, defer, or reroute observability. Typical effects include suppressing high-rate engineering streams in favor of minimal beacons, delaying playback of time periods of interest, replaying benign segments, or redirecting packets to alternate virtual channels that are not routinely monitored. Telemetry continues to flow, but it no longer reflects the activity the operators need to see. | |
| DE-0003.07 | Cryptographic Modes | Many missions separate authentication from confidentiality and allow on-orbit selection of algorithms, keys, profiles, or “crypto off/clear” states. Adversaries manipulate these mode controls and selectors to desynchronize ground and space or to hide content: flipping to a profile that the ground is not using, requesting clear telemetry while maintaining authenticated uplink, or rotating key IDs so frames validate internally but appear undecodable to external tools. Mode indicators and status words can also be biased so ground displays show expected settings while the link actually operates under attacker-chosen parameters, masking command and data exchanges within normal-looking traffic. | |
| DE-0003.08 | Received Commands | Spacecraft typically maintain histories of accepted, rejected, and executed commands, buffers, logs, or file records that can be downlinked on demand or periodically. An adversary conceals activity by editing or pruning these artifacts: removing entries, altering opcodes or arguments, rewriting timestamps and source identifiers, rolling logs early, or repopulating with benign-looking commands to balance counters. Related acknowledgments and event records may be suppressed or reclassified so cross-checks appear consistent. After manipulation, the official command history shows a plausible narrative that omits or mischaracterizes the adversary’s actions. | |
| DE-0003.10 | 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. | |
| DE-0003.11 | Watchdog Timer (WDT) for Evasion | By modifying watchdog parameters or who “pets” them, an adversary shapes what evidence survives. Extending or disabling timeouts allows long-running processes to operate without forced resets that would expose abnormal CPU or power usage; conversely, shortening windows or relocating the petting source to a low-level ISR can induce frequent resets that wipe volatile traces, break correlation in logs, and explain anomalies as “spurious reboots.” In both directions, the watchdog becomes a timing tool for hiding activity rather than a guardrail against it. | |
| DE-0003.12 | Poison AI/ML Training for Evasion | When security monitoring relies on AI/ML (e.g., anomaly detection on telemetry, RF fingerprints, or command semantics), the training data itself is a target. Data-poisoning introduces crafted examples or labels so the learned model embeds false associations, treating attacker behaviors as normal, or flagging benign patterns instead. Variants include clean-label backdoors keyed to subtle triggers, label flipping that shifts decision boundaries, and biased sampling that suppresses rare-but-critical signatures. Models trained on tainted corpora are later deployed as routine updates; once in service, the adversary presents inputs containing the trigger or profile they primed, and the detector omits or downranks the very behaviors that would reveal the intrusion. | |
| DE-0006 | Modify Whitelist | Threat actors may target whitelists on the spacecrafts as a means to execute and/or hide malicious processes/programs. Whitelisting is a common technique used on traditional IT systems but has also been used on spacecrafts. Whitelisting is used to prevent execution of unknown or potentially malicious software. However, this technique can be bypassed if not implemented correctly but threat actors may also simply attempt to modify the whitelist outright to ensure their malicious software will operate on the spacecraft that utilizes whitelisting. | |
| DE-0010 | Overflow Audit Log | The adversary hides activity by exhausting finite on-board logging and telemetry buffers so incriminating events are overwritten before they can be downlinked. Spacecraft typically use ring buffers with severity filters, per-subsystem quotas, and scheduled dump windows; by generating bursts of benign but high-frequency events (file listings, status queries, low-severity housekeeping, repeated mode toggles) or by provoking chatter from chatty subsystems, the attacker accelerates rollover. Variants target recorder indexes and event catalogs so new entries displace older ones, or they align floods with known downlink gaps and pass handovers when retention is shortest. To analysts on the ground, logs appear present but incomplete, showing a plausible narrative that omits the very interval when unauthorized commands or updates occurred. | |
| EXF-0006 | Modify Communications Configuration | The adversary alters radio/optical link configuration so the spacecraft emits mission data over paths the program does not monitor or control. Levers include retuning carriers, adding sidebands or subcarriers, changing modulation/coding profiles, remapping virtual channels/APIDs, editing beacon content, or redirecting routing tables in regenerative payloads. Data can be embedded steganographically (idle fields, padding, frame counters, pilot tones) or carried on a covert auxiliary downlink/crosslink pointed at attacker-owned apertures. Because these emissions conform to plausible waveforms and scheduler behavior, they appear as ordinary link activity while quietly conveying payload products, housekeeping, or file fragments to non-mission receivers. | |
| EXF-0006.01 | Software Defined Radio | Programmable SDRs let an attacker introduce new waveforms or piggyback payloads into existing ones. By modifying DSP chains (filters, mixers, FEC, framing), the actor can: add a low-rate subcarrier under the main modulation, alter preamble/pilot sequences to encode bits, vary puncturing/interleaver patterns as a covert channel, or schedule brief “maintenance” bursts that actually carry exfiltrated data. Changes may be packaged as legitimate updates or configuration profiles so the SDR transmits toward attacker-visible geometry using standard equipment, while mission tooling interprets the emission as routine. | |
| EXF-0006.02 | Transponder | On bent-pipe or regenerative transponders, configuration controls what is translated, amplified, and routed. An adversary can remap input–output paths, shift translation frequencies, adjust polarization or gain to favor non-mission receivers, or enable auxiliary ports so selected virtual channels or recorder playbacks are forwarded outside the planned ground segment. In regenerative systems, edited routing tables or QoS rules can mirror traffic to an attacker-controlled endpoint. The result is a sanctioned-looking carrier that quietly delivers mission data to unauthorized listeners. | |