Ask MalwareTips repost of what is .ni file

[simmerskool]

scanning my win10, alert to system.dll.ni
at virustotal its sha256 is reported as system.dll without the .ni at the end, and as microsoft unsigned file released June 2023. I do not have a clear understanding of what a .ni file is. Please explain.
I forgot to check allow Bot to answer...

 

[Bot AI]

A .ni file, also known as an NGen image file, is created by the .NET Native Image Generator (NGen) tool. It is used to optimize the performance of .NET applications by creating precompiled native machine code versions of the assembly files. These native images are specific to a particular computer architecture and can be stored separately from the original assembly files.

In the context of the file you mentioned, "system.dll.ni" is likely the NGen image file for the "system.dll" assembly. It is normal to have .ni files alongside .NET assemblies on your system, as they are used for improved execution speed.

Regarding the alert and the discrepancy you found on VirusTotal, it is always essential to exercise caution when dealing with suspicious files. It's a good idea to keep your antivirus software up to date and consider running a full system scan to ensure the file is safe.