Technique:  Process Injection
During the 2015 Ukraine Electric Power Attack, It loaded BlackEnergy into svchost.exe, which then launched iexplore.exe for their C2.
ABK has the ability to inject shellcode into svchost.exe.
Agent Tesla can inject into known, vulnerable binaries on targeted hosts.
ANDROMEDA can inject into the wuauclt.exe process to perform C2 actions.
It malware has injected a Cobalt Strike beacon into Rundll32.exe.
It injects its malware variant, ROKRAT, into the cmd.exe process.
It malware TIDYELF loaded the main WINTERLOVE component by injecting it into the iexplore.exe process.
Attor's dispatcher can inject itself into running processes to gain higher privileges and to evade detection.
AuditCred can inject code from files to other running processes.
Avenger has the ability to inject shellcode into svchost.exe.
Backdoor.Oldrea injects itself into explorer.exe.
BADHATCH can inject itself into an existing explorer.exe process by using RtlCreateUserThread.
Bazar can inject code through calling VirtualAllocExNuma.
BBK has the ability to inject shellcode into svchost.exe.
Bumblebee can inject code into multiple processes on infected endpoints.
Cardinal RAT injects into a newly spawned process created from a native Windows executable.
Clambling can inject into the svchost.exe process for execution.
It has injected code into trusted processes.
Cobalt Strike can inject a variety of payloads into processes dynamically chosen by the adversary.
CostaBricks can inject a payload into the memory of a compromised host.
Donut includes a subproject DonutTest to inject shellcode into a target process.
Dyre has the ability to directly inject its code into the web browser process.
Egregor can inject its payload into iexplore.exe process.
Empire contains multiple modules for injecting into processes, such as Invoke-PSInject.
Gazer injects its communication module into an Internet accessible process through which it performs C2.
gh0st RAT can inject malicious code into process created by the "Command_Create&Inject" function.
GuLoader has the ability to inject shellcode into a donor processes that is started in a suspended state. GuLoader has previously used RegAsm as a donor process.
HOPLIGHT has injected into running processes.
HTRAN can inject into into running processes.
HyperBro can run shellcode it injects into a newly created process.
InvisiMole can inject itself into another process to avoid detection including use of a technique called ListPlanting that customizes the sorting algorithm in a ListView structure.
IronNetInjector can use an IronPython scripts to load a .NET injector to inject a payload into its own or a remote process.
JHUHUGIT performs code injection injecting its own functions to browser processes.
JPIN can inject content into lsass.exe to load a module.
It has used Win7Elevate to inject malicious code into explorer.exe.
Lizar can migrate the loader into another process.
metaMain can inject the loader file, Speech02.db, into a process.
Mis-Type has been injected directly into a running process, including explorer.exe.
NavRAT copies itself into a running Internet Explorer process to evade detection.
NETWIRE can inject code into system processes including notepad.exe, svchost.exe, and vbc.exe.
During Operation Sharpshooter, threat actors leveraged embedded shellcode to inject a downloader into the memory of Word.
During Operation Wocao, threat actors injected code into a selected process, which in turn launches a command as a child process of the original.
Pandora can start and inject code into a new svchost process.
The PcShare payload has been injected into the logagent.exe and rdpclip.exe processes.
It has used various methods of process injection including hot patching.
PoshC2 contains multiple modules for injecting into processes, such as Invoke-PSInject.
QakBot can inject itself into processes including explore.exe, Iexplore.exe, Mobsync.exe., and wermgr.exe.
Remcos has a command to hide itself through injecting into another process.
REvil can inject itself into running processes on a compromised host.
ROKRAT can use VirtualAlloc, WriteProcessMemory, and then CreateRemoteThread to execute shellcode within the address space of Notepad.exe.
Ryuk has injected itself into remote processes to encrypt files using a combination of VirtualAlloc, WriteProcessMemory, and CreateRemoteThread.
ShadowPad has injected an install module into a newly created process.
It has injected a DLL library containing a Trojan into the fwmain32.exe process.
SILENTTRINITY can inject shellcode directly into Excel.exe or a specific process.
Sliver can inject code into local and remote processes.
SLOTHFULMEDIA can inject into running processes on a compromised host.
Smoke Loader injects into the Internet Explorer process.
StoneDrill has relied on injecting its payload directly into the process memory of the victim's preferred browser.
It has injected malicious code into legitimate .NET related processes including  regsvcs.exe, msbuild.exe, and installutil.exe.
TrickBot has used Nt* Native API functions to inject code into legitimate processes such as wermgr.exe.
TSCookie has the ability to inject code into the svchost.exe, iexplorer.exe, explorer.exe, and default browser processes.
It has also used PowerSploit's Invoke-ReflectivePEInjection.ps1 to reflectively load a PowerShell payload into a random process on the victim system.
WarzoneRAT has the ability to inject malicious DLLs into a specific process for privilege escalation.
Waterbear can inject decrypted shellcode into the LanmanServer service.
Wiarp creates a backdoor through which remote attackers can inject files into running processes.
Wingbird performs multiple process injections to hijack system processes and execute malicious code.
It has used process injection to execute payloads to escalate privileges.
Woody RAT can inject code into a targeted process by writing to the remote memory of an infected system and then create a remote thread.