PACKWIN
From Just Solve the File Format Problem
PACKWIN is an executable compression utility. It is credited to Lei Jun and Wang Quanguo, and Yellow Rose Workgroup.
Despite its name, the software runs on DOS. It compresses DOS EXE files, and Windows 3.1 EXE files.
Identification
Compressed DOS EXE files made by v1.0α have ASCII text "YRZLITE (C) 1993 WYellow Rose" at offset 30.
Compressed Windows EXE files usually have "STUBYellow Rose Software Co. LEI" at offset 28. [TODO: This signature is not present if the /w (disable Winstub compression) option was used. It's not obvious how to identify such files.]
