Query: Outbound C2 pattern associated with Path Interception by Unquoted Path
Matching passage: T1574.009 Path Interception by Unquoted Path. Tactics: stealth, execution. Description: Adversaries may execute their own malicious payloads by hijacking vulnerable file path references. Adversaries can take advantage of paths that lack surrounding quotations by placing an executable in a higher level directory within the path, so that Windows will choose the adversary's executable to launch. Service paths (Citation: Microsoft CurrentControlSet Services) and shortcut paths may also be vulnerable to path interception if the path has one or more spaces and is not surrounded by quotation marks (e.g., <code>C:\unsafe path with space\program.exe</code> vs. <code>"C:\safe path with space\program.exe"</code>). (Citation: Help eliminate unquoted path) (stored in Windows Registry keys) An adversary can place an executable in a higher level directory of the path, and Windows will resolve that executable instead of the intended executable. For example, if the path in a shortcut is <code>C:\program files\myapp.exe</code>, an adversary may create a program at <code>C:\program.exe</code> that will be run instead of the intended program. (Citation: Windows Unquoted Services) (Citation: Windows Privilege Escalation Guide) This technique can be used for persistence if executables are called on a regular basis, as well as privilege escalation if intercepted executables are started by a higher privileged process.
Near-miss passage: T1574.013 KernelCallbackTable. Tactics: stealth, execution. Description: Adversaries may abuse the <code>KernelCallbackTable</code> of a process to hijack its execution flow in order to run their own payloads.(Citation: Lazarus APT January 2022)(Citation: FinFisher exposed ) The <code>KernelCallbackTable</code> can be found in the Process Environment Block (PEB) and is initialized to an array of graphic functions available to a GUI process once <code>user32.dll</code> is loaded.(Citation: Windows Process Injection KernelCallbackTable) An adversary may hijack the execution flow of a process using the <code>KernelCallbackTable</code> by replacing an original callback function with a malicious payload. Modifying callback functions can be achieved in various ways involving related behaviors such as [Reflective Code Loading](https://attack.mitre.org/techniques/T1620) or [Process Injection](https://attack.mitre.org/techniques/T1055) into another process. A pointer to the memory address of the <code>KernelCallbackTable</code> can be obtained by locating the PEB (ex: via a call to the <code>NtQueryInformationProcess()</code> [Native API](https://attack.mitre.org/techniques/T1106) function).(Citation: NtQueryInformationProcess) Once the pointer is located, the <code>KernelCallbackTable</code> can be duplicated, and a function in the table (e.g., <code>fnCOPYDATA</code>) set to the address of a malicious payload (ex: via <code>WriteProcessMemory()</code>). The PEB is then updated with the new address of the table. Once the tampered function is invoked, the malicious payload will be triggered.(Citation: Lazarus APT January 2022) The tampered function is typically invoked using a Windows message. After the process is hijacked and malicious code is executed, the <code>KernelCallbackTable</code> may also be restored to its original state by the rest of the malicious payload.(Citation: Lazarus APT January 2022) Use of the <code>KernelCallbackTable</code> to hijack execution flow may evade detection from security products since the execution can be mask