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Syscall Table Hooking Detection


The SyscallTableHooking signature is developed to detect malevolent hooking of the syscall table in a system.

System calls (syscalls) serve as the pivotal bridge between user applications and the operating system kernel. If manipulated through hooking, they grant an adversary the capability to exert substantial control over vital system functions.


Syscalls are essential; they act as intermediaries enabling user applications to request services and operations from the OS kernel. A table in the kernel catalogs these syscalls.

If a malicious actor manages to manipulate or "hook" into this table, they gain the ability to either supplant or entirely circumvent the kernel's innate operations. This control ranges from basic operations like reading/writing files to advanced capabilities like influencing the system's behavior or even rerouting its execution flow. In simple terms, an attacker could make the system believe it's performing regular operations when it's, in fact, executing the attacker's code.

Rootkits, notorious for deep system infiltration, often exploit syscall table hooking. It's a strong indication that the system's kernel may have been compromised. Furthermore, any modules hiding in the shadows, known as "hidden modules," also hint at a deeper malfeasance and indicate an elevated threat level.


The signature SyscallTableHooking is meticulously designed to detect instances where the syscall table is tampered with in real-time. By spotting these hooks early, it provides a pivotal advantage in thwarting and neutralizing potential threats, preserving the sanctity of the kernel and the entire system.


  • ID: TRC-1030
  • Version: 1
  • Name: Syscall table hooking detected
  • EventName: syscall_hooking
  • Description: It focuses on detecting unauthorized and malevolent hooking of the syscall table. This manipulation allows an attacker to exert undue control over the kernel's operations, leading to potential compromises of the entire system. Rootkits often employ this technique, making it a critical threat to detect and address.
  • Properties:
  • Severity: 3 (Moderate to high threat level)
  • Category: defense-evasion
  • Technique: Rootkit
  • Kubernetes_Technique: N/A
  • id: attack-pattern--0f20e3cb-245b-4a61-8a91-2d93f7cb0e9b
  • external_id: T1014


Upon discovering a malevolent hook in the syscall table, the signature generates a Finding that houses:

  • SigMetadata: This is a set of metadata outlining the nature and potential threat of the detected issue.
  • Event: A comprehensive record of the event that spurred the detection, offering a granular look at the problem.
  • Data: This highlights the specific syscalls that have been manipulated, giving insights into the nature and extent of the threat.

Events Used

The signature predominantly zeroes in on the event:

  • hooked_syscalls: This event is fired when malicious hooking of the syscall table is detected. The signature parses this event's data to ascertain the degree and nature of the hooking.