Query: mitigate Asynchronous Procedure Call
Matching passage: T1055.004 Asynchronous Procedure Call. Tactics: stealth, privilege escalation. Description: Adversaries may inject malicious code into processes via the asynchronous procedure call (APC) queue in order to evade process-based defenses as well as possibly elevate privileges. APC injection is a method of executing arbitrary code in the address space of a separate live process. APC injection is commonly performed by attaching malicious code to the APC Queue (Citation: Microsoft APC) of a process's thread. Queued APC functions are executed when the thread enters an alterable state.(Citation: Microsoft APC) A handle to an existing victim process is first created with native Windows API calls such as <code>OpenThread</code>. At this point <code>QueueUserAPC</code> can be used to invoke a function (such as <code>LoadLibrayA</code> pointing to a malicious DLL). A variation of APC injection, dubbed "Early Bird injection", involves creating a suspended process in which malicious code can be written and executed before the process' entry point (and potentially subsequent anti-malware hooks) via an APC. (Citation: CyberBit Early Bird Apr 2018) AtomBombing (Citation: ENSIL AtomBombing Oct 2016) is another variation that utilizes APCs to invoke malicious code previously written to the global atom table.(Citation: Microsoft Atom Table) Running code in the context of another process may allow access to the process's memory, system/network resources, and possibly elevated privileges. Execution via APC injection may also evade detection from security products since the execution is masked under a legitimate process.
Near-miss passage: T1055.015 ListPlanting. Tactics: stealth, privilege escalation. Description: Adversaries may abuse list-view controls to inject malicious code into hijacked processes in order to evade process-based defenses as well as possibly elevate privileges. ListPlanting is a method of executing arbitrary code in the address space of a separate live process.(Citation: Hexacorn Listplanting) Code executed via ListPlanting may also evade detection from security products since the execution is masked under a legitimate process. List-view controls are user interface windows used to display collections of items.(Citation: Microsoft List View Controls) Information about an application's list-view settings are stored within the process' memory in a <code>SysListView32</code> control. ListPlanting (a form of message-passing "shatter attack") may be performed by copying code into the virtual address space of a process that uses a list-view control then using that code as a custom callback for sorting the listed items.(Citation: Modexp Windows Process Injection) Adversaries must first copy code into the target process’ memory space, which can be performed various ways including by directly obtaining a handle to the <code>SysListView32</code> child of the victim process window (via Windows API calls such as <code>FindWindow</code> and/or <code>EnumWindows</code>) or other [Process Injection](https://attack.mitre.org/techniques/T1055) methods. Some variations of ListPlanting may allocate memory in the target process but then use window messages to copy the payload, to avoid the use of the highly monitored <code>WriteProcessMemory</code> function. For example, an adversary can use the <code>PostMessage</code> and/or <code>SendMessage</code> API functions to send <code>LVM_SETITEMPOSITION</code> and <code>LVM_GETITEMPOSITION</code> messages, effectively copying a payload 2 bytes at a time to the allocated memory.(Citation: ESET InvisiMole June 2020) Finally, the payload is triggered by sending the <code>LVM_SORTITEMS</code> message to the <code>SysListView32</code>