| ueaf | Protector Suite QL Encrypted Data |
| uf2 | USB Flashing Format Data |
| ugoira | pixiv Ugoira Animated Image |
| uls | Microsoft NetMeeting User Location Service File |
| unf | Universal NES Image Format ROM |
| unif | Universal NES Image Format ROM |
| up5 | Baby Lock Sewing Machine Software Update |
| upc | Ultimate Paint Graphics Editor Plugin |
| urc | Unicenter Remote Control Script |
| url | Internet Shortcut |
| urm | Unreal Engine 2 Runtime Executable File |
| utz | UIQ Theme Package |
| uxz | IBM Flex System Firmware Update |
| v2u | TI Voyage 200 System Update |
| v3f | ADP v3 Application |
| v6f | ADP v6 Application |
| vbee | EmEditor VBScript Macro |
| vbn | Symantec Antivirus Quarantine File |
| vboxlm | Vbox Data |
| vca | VAKCER Project Tracker COM Add-in |
| vcf | Vevi Configuration File |
| vdplugin | VirtualDub Plugin File |
| vee | Agilent VEE Program |
| ver | Version Information |
| vfj | Personal Backup Saved Task |
| vfp | TMPGenc VFAPI Plugin |
| vg2 | Polycom PVX VG2 Log |
| vgj | BMC Server Automation Virtual Guest Job |
| vi1 | Virus-Infected File |
| vi2 | Virus-Infected File |
| vid | MS-DOS Video Driver |
| viivo | Viivo Encrypted Data |
| vir | Virus-Infected File |
| vl | Citrix Program Neighborhood Database File |
| vlt | WinVault File Archive |
