Detection of cryptographic keys being used repeatedly from unexpected or unauthorized locations, indicating potential misuse of valid cryptographic credentials to maintain persistent access to spacecraft systems.

STIX Pattern

[x-opencti-cryptographic-key:usage_location != 'authorized_locations' AND x-opencti-cryptographic-key:use_count > 'threshold']

SPARTA TTPs

ID	Name	Description
REC-0001.03	Cryptographic Algorithms	Adversaries look for the complete crypto picture: algorithms and modes, key types and lifecycles, authentication schemes, counter or time-tag handling, anti-replay windows, link-layer protections, and any differences between uplink and downlink policy. With algorithm and key details, a threat actor can craft valid telecommands, masquerade as a trusted endpoint, or degrade availability through replay and desynchronization. Sources include interface specifications, ground software logs, test vectors, configuration files, contractor laptops, and payload-specific ICDs that reuse bus-level credentials. Particular risk arises when command links rely on authentication without confidentiality; once an adversary acquires the necessary keys or counters, they can issue legitimate-looking commands outside official channels. Programs should assume that partial disclosures, MAC length, counter reset rules, or key rotation cadence, aid exploitation.
RD-0003.02	Cryptographic Keys	Adversaries seek any cryptographic material that confers command or decryption authority: uplink authentication/MAC keys and counters, link-encryption/session keys and KEKs, loading/transfer keys for HSMs, PN/spreading codes, modem credentials, and station or crosslink keys. Acquisition routes include compromised ground systems and laptops, misconfigured repositories and ticket systems, memory/core dumps, training datasets and screenshots, contractor support channels, and poorly controlled key-loading or recovery procedures. Because some missions authenticate uplink without encrypting it, possession of the right keys/counters may be sufficient to inject accepted commands outside official channels or to desynchronize anti-replay.
IA-0008	Rogue External Entity	Adversaries obtain a foothold by interacting with the spacecraft from platforms outside the authorized ground architecture. A “rogue external entity” is any actor-controlled transmitter or node, ground, maritime, airborne, or space-based, that can radiate or exchange traffic using mission-compatible waveforms, framing, or crosslink protocols. The technique exploits the fact that many vehicles must remain commandable and discoverable over wide areas and across multiple modalities. Using public ephemerides, pass predictions, and knowledge of acquisition procedures, the actor times transmissions to line-of-sight windows, handovers, or maintenance periods. Initial access stems from presenting traffic that the spacecraft will parse or prioritize: syntactically valid telecommands, crafted ranging/acquisition exchanges, crosslink service advertisements, or payload/user-channel messages that bridge into the command/data path.
IA-0008.01	Rogue Ground Station	Adversaries may field their own ground system, transportable or fixed, to transmit and receive mission-compatible signals. A typical setup couples steerable apertures and GPS-disciplined timing with SDR/modems configured for the target’s bands, modulation/coding, framing, and beacon structure. Using pass schedules and Doppler/polarization predictions, the actor crafts over-the-air traffic that appears valid at the RF and protocol layers.
IA-0008.02	Rogue Spacecraft	Adversaries may employ their own satellite or hosted payload to achieve proximity and a privileged RF geometry. After phasing into the appropriate plane or drift orbit, the rogue vehicle operates as a local peer: emitting narrow-beam or crosslink-compatible signals, relaying user-channel traffic that the target will honor, or advertising services that appear to originate from a trusted neighbor. Close range reduces path loss and allows highly selective interactions, e.g., targeted spoofing of acquisition exchanges, presentation of crafted routing/time distribution messages, or injection of payload tasking that rides established inter-satellite protocols. The rogue platform can also perform spectrum and protocol reconnaissance in situ, refining message formats and timing before attempting first execution.
PER-0005	Credentialed Persistence	Threat actors may acquire or leverage valid credentials to maintain persistent access to a spacecraft or its supporting command and control (C2) systems. These credentials may include system service accounts, user accounts, maintenance access credentials, cryptographic keys, or other authentication mechanisms that enable continued entry without triggering access alarms. By operating with legitimate credentials, adversaries can sustain access over extended periods, evade detection, and facilitate follow-on tactics such as command execution, data exfiltration, or lateral movement. Credentialed persistence is particularly effective in environments lacking strong credential lifecycle management, segmentation, or monitoring allowing threat actors to exploit trusted pathways while remaining embedded in mission operations.
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-0004	Masquerading	The adversary presents themselves as an authorized origin so activity appears legitimate across RF, protocol, and organizational boundaries. Techniques include crafting telecommand frames with correct headers, counters, and dictionaries; imitating station “fingerprints” such as Doppler, polarization, timing, and framing; replaying or emulating crosslink identities; and using insider-derived credentials or roles to operate mission tooling. Masquerading can also target metadata, virtual channel IDs, APIDs, source sequence counts, and facility identifiers, so logs and telemetry attribute actions to expected entities. The effect is that commands, file transfers, or configuration changes are processed as if they came from approved sources, reducing scrutiny and delaying detection.