Detection of a user account or cryptographic key being used outside of the expected operational time windows. This may indicate unauthorized or suspicious activity, such as a threat actor using valid credentials or cryptographic keys to gain or maintain persistent access to the spacecraft or related systems.

STIX Pattern

[user-account:last_login_time != 'expected_operational_hours' OR x-opencti-cryptographic-key:usage_time != 'expected_usage_time']

SPARTA TTPs

ID	Name	Description
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-0007	Compromise Ground System	Compromising the ground segment gives an adversary the most direct path to first execution against a spacecraft. Ground systems encompass operator workstations and mission control mission control software, scheduling/orchestration services, front-end processors and modems, antenna control, key-loading tools and HSMs, data gateways (SLE/CSP), identity providers, and cloud-hosted mission services. Once inside, a threat actor can prepare on-orbit updates, craft and queue valid telecommands, replay captured traffic within acceptance windows, or manipulate authentication material and counters to pass checks. The same foothold enables deep reconnaissance: enumerating mission networks and enclaves, discovering which satellites are operated from a site, mapping logical topology between MOC and stations, identifying in-band “birds” reachable from a given aperture, and learning pass plans, dictionaries, and automation hooks. From there, initial access to the spacecraft is a matter of timing and presentation, injecting commands, procedures, or update packages that align with expected operations so the first execution event appears indistinguishable from normal activity.
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.
IA-0009	Trusted Relationship	Adversaries obtain first execution by riding connections that the mission already trusts, formal interconnections with partners, vendors, and user communities. Once a third party is compromised, the actor inherits that entity’s approved routes into mission enclaves: VPNs and jump hosts into ground networks, API keys into cloud tenants, automated file drops that feed command or update pipelines, and collaboration spaces where procedures and dictionaries circulate. Because traffic, credentials, and artifacts originate from known counterparts, the initial execution event can appear as a routine payload task, scheduled procedure, or software update promoted through established processes.
IA-0009.01	Mission Collaborator (academia, international, etc.)	Missions frequently depend on distributed teams, instrument builders at universities, science operations centers, and international partners, connected by data portals, shared repositories, and federated credentials. A compromise of a collaborator yields access to telescience networks, analysis pipelines, instrument commanding tools, and file exchanges that deliver ephemerides, calibration products, procedures, or configuration tables into mission workflows. Partners may operate their own ground elements or payload gateways under delegated authority, creating additional entry points whose authentication and logging differ from the prime’s. Initial access emerges when attacker-modified artifacts or commands traverse these sanctioned paths: a revised calibration script uploaded through a science portal, a configuration table promoted by a cross-org CI job, or a payload task submitted via a collaboration queue and forwarded by the prime as routine work. Variations in process rigor, identity proofing, and toolchains across institutions amplify the attacker’s options while preserving the appearance of legitimate partner activity.
IA-0009.02	Vendor	Vendors that design, integrate, or support mission systems often hold elevated, persistent routes into operations: remote administration of ground software and modems, access to identity providers and license servers, control of cloud-hosted services, and authority to deliver firmware, bitstreams, or patches. Attackers who compromise a vendor’s enterprise or build environment can assume these roles, issuing commands through approved consoles, queuing updates in provider-operated portals, or invoking maintenance procedures that the mission expects the vendor to perform. Some vendor pathways terminate directly on RF equipment or key-management infrastructure; others ride cross-account cloud roles or managed SaaS backends that handle mission data and scheduling.
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.
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.
EXF-0007	Compromised Ground System	The adversary resides in mission ground infrastructure and uses its trusted position to siphon data at scale. With access to operator workstations, mission control servers, baseband/modem chains, telemetry processing pipelines, or archive databases, the attacker can mirror real-time streams, scrape recorder playbacks, export payload products, and harvest procedure logs and command histories. Because exfiltration rides normal paths, file staging areas, data distribution services, cloud relays, or cross-site links, it blends with routine dissemination. Compromise of scheduling tools and pass plans also lets the actor time captures to high-value downlinks and automate bulk extraction without touching the spacecraft.