Detection of abnormal system calls originating from processes or binaries that are unexpected or not typically associated with certain system operations. This could indicate malicious activity such as the execution of a backdoor or malicious code, where the software is making system calls outside of its normal behavior.

STIX Pattern

[process:image_ref.name = 'unexpected_process' AND process:system_call = 'unexpected_system_call']

SPARTA TTPs

ID	Name	Description
IA-0001	Compromise Supply Chain	Threat actors may manipulate or compromise products or product delivery mechanisms before the customer receives them in order to achieve data or system compromise.
IA-0001.02	Software Supply Chain	Threat actors may manipulate software binaries and applications prior to the customer receiving them in order to achieve data or system compromise. This attack can take place in a number of ways, including manipulation of source code, manipulation of the update and/or distribution mechanism, or replacing compiled versions with a malicious one.
EX-0009.02	Operating System	Threat actors may exploit flaws in the operating system code, which controls the storage, memory management, provides resources to the FSW, and controls the bus. There has been a trend where some modern spacecraft are running Unix-based operating systems and establishing SSH connections for communications between the ground and spacecraft. Threat actors may seek to gain access to command line interfaces & shell environments in these instances. Additionally, most operating systems, including real-time operating systems, include API functionality for operator interaction. Threat actors may seek to exploit these or abuse a vulnerability/misconfiguration to maliciously execute code or commands.
EX-0010	Malicious Code	Threat actors may rely on other tactics and techniques in order to execute malicious code on the victim spacecraft. This can be done via compromising the supply chain or development environment in some capacity or taking advantage of known commands. However, once malicious code has been uploaded to the victim spacecraft, the threat actor can then trigger the code to run via a specific command or wait for a legitimate user to trigger it accidently. The code itself can do a number of different things to the hosted payload, subsystems, or underlying OS.
EX-0010.01	Ransomware	Threat actors may encrypt spacecraft data to interrupt availability and usability. Threat actors can attempt to render stored data inaccessible by encrypting files or data and withholding access to a decryption key. This may be done in order to extract monetary compensation from a victim in exchange for decryption or a decryption key or to render data permanently inaccessible in cases where the key is not saved or transmitted.
EX-0010.02	Wiper Malware	Threat actors may deploy wiper malware, which is a type of malicious software designed to destroy data or render it unusable. Wiper malware can spread through various means, software vulnerabilities (CWE/CVE), or by exploiting weak or stolen credentials.
EX-0010.03	Rootkit	Rootkits are programs that hide the existence of malware by intercepting/hooking and modifying operating system API calls that supply system information. Rootkits or rootkit enabling functionality may reside at the flight software or kernel level in the operating system or lower, to include a hypervisor, Master Boot Record, or System Firmware.
EX-0012.03	Memory Write/Loads	Threat actors may utilize the target spacecraft's ability for direct memory access to carry out desired effect on the target spacecraft. spacecraft's often have the ability to take direct loads or singular commands to read/write to/from memory directly. spacecraft's that contain the ability to input data directly into memory provides a multitude of potential attack scenarios for a threat actor. Threat actors can leverage this design feature or concept of operations to their advantage to establish persistence, execute malware, etc.
EX-0012.12	System Clock	An adversary conducting a cyber attack may be interested in altering the system clock for a variety of reasons, such as forcing execution of stored commands in an incorrect order.
PER-0002	Backdoor	Threat actors may find and target various backdoors, or inject their own, within the victim spacecraft in the hopes of maintaining their attack.
PER-0002.02	Software	Threat actors may inject code to create their own backdoor to establish persistent access to the spacecraft. This may be done through modification of code throughout the software supply chain or through modification of the software-defined radio configuration (if applicable).