Depending on where you encountered the file, "LSM" likely refers to one of the following:
: To view the contents, you must have all parts of the archive in the same folder. Opening "Part01" with software like WinRAR or 7-Zip will automatically pull data from the subsequent parts to reconstruct the original file. Potential Contexts for "LSM"
While the RAR format itself is not inherently dangerous, it can be used to hide malicious executables. MCO 5800.16 W/CH 1-7 W/VOL 1-17 - Marines.mil
: In enterprise environments, it may be an Oracle Server backup managed by the Legato Storage Manager .