The calc entry is a suspicious registry entry that should be investigated first by the analyst. The calc entry is located in the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run registry key, which is a common location for malware to persist and execute on system startup. The calc entry has a data value of “C:\Windows\System32\calc.exe”, which is the path to the legitimate Windows Calculator program. However, this program does not need to run on system startup, and it could be a disguise for a malicious executable that has replaced or renamed the original calculator program. The calc entry could also be a sign of a fileless malware attack, where the attacker uses the legitimate calculator program to execute malicious commands or scripts in memory1.
