T1218.013_mavinject

T1218.013 Mavinject

Sub-technique of: T1218

High-Level Description

Adversaries may abuse mavinject.exe to proxy execution of malicious code. Mavinject.exe is the Microsoft Application Virtualization Injector, a Windows utility that can inject code into external processes as part of Microsoft Application Virtualization (App-V).

Adversaries may abuse mavinject.exe to inject malicious DLLs into running processes (i.e. Dynamic-link Library Injection), allowing for arbitrary code execution (ex. C:\Windows\system32\mavinject.exe PID /INJECTRUNNING PATH_DLL). Since mavinject.exe may be digitally signed by Microsoft, proxying execution via this method may evade detection by security products because the execution is masked under a legitimate process.

In addition to Dynamic-link Library Injection, Mavinject.exe can also be abused to perform import descriptor injection via its /HMODULE command-line parameter (ex. mavinject.exe PID /HMODULE=BASE_ADDRESS PATH_DLL ORDINAL_NUMBER). This command would inject an import table entry consisting of the specified DLL into the module at the given base address.

Kill Chain Phase

• Defense Evasion (TA0005)

Platforms: Windows

What to Check

• Identify if Mavinject technique is applicable to target environment
• Check Windows systems for indicators of Mavinject
• Verify mitigations are bypassed or absent (2 known mitigations)
• Assess detection coverage (1 detection strategies)

How to Test

Manual Testing

1. Identify Attack Surface: Determine if the target environment is susceptible to Mavinject by examining the target platforms (Windows).

2. Assess Existing Defenses: Review whether mitigations for T1218.013 are in place. If defenses are absent or misconfigured, this technique may be exploitable.

3. Execute Test: Use tools and methods described in the MITRE ATT&CK page and external references below.

Note: No Atomic Red Team tests available for this technique. See Atomic Red Team GitHub for updates.

Remediation Guide

M1042 Disable or Remove Feature or Program

Consider removing mavinject.exe if Microsoft App-V is not used within a given environment.

M1038 Execution Prevention

Use application control configured to block execution of mavinject.exe if it is not required for a given system or network to prevent potential misuse by adversaries.

Detection

Detecting Code Injection via mavinject.exe (App-V Injector)

Risk Assessment

CWE Categories

References

• ATT Lazarus TTP Evolution
• LOLBAS Mavinject
• Mavinject Functionality Deconstructed
• Reaqta Mavinject
• Atomic Red Team - T1218.013
• MITRE ATT&CK - T1218.013