process::list lists all the running processes. It uses the NtQuerySystemInformation Windows Native API function.
mimikatz # process::list
4 System
92 Registry
396 smss.exe
492 csrss.exe
608 wininit.exe
736 services.exe
752 lsass.exe
864 svchost.exe
888 fontdrvhost.exe
952 svchost.exe
1000 svchost.exe
...Output Omitted...