Why would someone split a file into parts like SS-Ntl-017_v.7z.002 ?

According to the MITRE ATT&CK framework , "Obfuscated Files" are a common tactic for defense evasion. Always ensure you trust the source before merging and running files from a split archive.

Obfuscated Files or Information, Technique T1027 - MITRE ATT&CK®

: This is a unique identifier. "Ntl" frequently stands for "National" or "Natural." For example, the National Theatre uses similar internal numbering for its digital recordings.