Is this a legit Avast File?

Is this a legit avast file?

AVAST Software\Avast\setup\59e26a0e-76b6–4d82-bd3f-80046765e6ae.exe

Is this a legit registry key modification?

“avast! Emergency Update may be trying to prevent “20131121” from running each time your computer
is started by modifying the registry key: HKLM\SOFTWARE\MICROSOFT\WINDOWS\CURRENTVERSION\RUN”

Yes it is legitimate.

Yes it is related to the avast emergency update function - this is a uniquely generated file name for your emergency update check and download.