Open SLF File
The SLF extension file is used by Symantec software to activate software licenses, hence the acronym, Symantec License File.
About Symantec
Symantec Corporation, today known as NortonLifeLock Inc., is an American software company based in Arizona, United States.
It is a company that offers cybersecurity software and services, with a presence in the Fortune 500 and a member of the S&P 500 stock index.
The SLF file contains activation codes that are registered with Symantec, and allow users to legally use a copy of Symtantec software.
Some editions of Symantec software do not require the installation of the SLF file.
SLF files, by their nature, are encrypted files that should not be attempted to be opened manually.