Providing the source of the file could help narrow down the specific "write-up" you need.
According to a recent automated malware analysis report from ANY.RUN , a file named CNI.rar was observed interacting with system processes like WinRAR.exe to perform write operations in a controlled environment. CNI.rar
Check the SHA-256 hash on platforms like VirusTotal to see if it matches known infostealers or trojans. Providing the source of the file could help
If you are dealing with this file as part of a security investigation or CTF, here is the standard procedure for a write-up: CNI.rar