title: Thread Execution Hijacking (T1055.003)
id: df00tech-t1055-003
status: experimental
description: "Adversaries may inject malicious code into hijacked processes in order to evade process-based defenses as well as possibly elevate privileges. Thread Execution Hijacking is commonly performed by suspending an existing process then unmapping/hollowing its memory, which can then be replaced with malicious code or the path to a DLL. A handle to an existing victim process is first created with native Windows API calls such as OpenThread. At this point the process can be suspended then written to, realigned to the injected code, and resumed via SuspendThread, VirtualAllocEx, WriteProcessMemory, SetThreadContext, then ResumeThread respectively. This is very similar to Process Hollowing but targets an existing process rather than creating a process in a suspended state."
references:
  - https://attack.mitre.org/techniques/T1055/003/
  - https://df00tech.com/detections/T1055.003
author: df00tech
date: 2026/04/18
tags:
  - attack.t1055.003
# NOTE: logsource is auto-derived and may need adjustment for your environment
logsource:
  category: process_creation
  product: windows
detection:
  # This detection logic could not be auto-translated; see the KQL/SPL query on df00tech.
  selection:
    EventID: '*'
  condition: selection
falsepositives:
  - "Debuggers (WinDbg, x64dbg, Visual Studio) using SetThreadContext to modify debuggee thread state"
  - Windows Error Reporting (WerFault.exe) suspending and inspecting crashed process threads
  - Anti-cheat software suspending and scanning game process threads for integrity
  - Application crash handlers that suspend threads to generate crash dumps
level: critical