In theory, these files could be infected but to date no LIB-file virus has been identified. Access files can contain macros that are powerful enough to be used for viruses and worms. According to Symantec these are database-related program files. Program File Overlay. Can be used for a variety of tasks associated with a program.
Overlays typically add functions to programs.
It's possible to infect overlay files but not usually likely. PowerPoint presentations can contain macros that are powerful enough to be used for viruses and worms. Rich Text Format. A format for transmitting formatted text usually assumed to be safe. RTF files can also be DOC files renamed and Word will open them as DOC files.