: RAR (Roshal Archive). This is a proprietary archive format used for high-ratio data compression and error recovery. Likely Origins
: Multi-part archives are a common vector for malware because security scanners often cannot see the "full picture" of the executable until all parts are combined.
: Automated backup systems often use date-stamped strings ( gf260721 ) for version control. Security Warning
gf260721 : Often represents a date (July 21, 2021) or a project code.