This detection rule targets the use of Rundll32.exe to load DLLs associated with the F-Secure C3 tool, which is known for evasive behavior. The primary indicator is the use of the command line that contains 'rundll32.exe' along with the parameters '.dll' and 'StartNodeRelay'. This suggests that the Rundll32 is being used in a specific manner to execute a potentially malicious or non-standard function exported by the DLL. As such, the detection focuses on monitoring process creation events to intercept attempts to execute this tool, which is commonly employed in post-exploitation scenarios. The level of threat attributed to this behavior is defined as critical, indicating a high-risk vector that organizations need to monitor closely.