| .cxa |
FMAT Listmode File |
| .cxr |
FMAT Plate Results File |
| .cws |
ChordWizard Song |
| .cpaa |
Captivate Shared Action File |
| .cptm |
Captivate Theme File |
| .cm5 |
Clone Manager File |
| .crypt8 |
WhatsApp Encrypted Database File |
| .comiclife |
Comic Life Document |
| .ciso |
Compact ISO File |
| .ccld |
Construction Clouds Data File |
| .cmr |
Coach Results File |
| .compiled |
Compiled Game Resource File |
| .caj |
Chinese Academic Journal File |
| .cpvc |
Adobe Captivate Video Composition |
| .cmate |
ControllerMate File |
| .cram |
Compressed Alignment File |
| .cenon~ |
Cenon Backup File |
| .clks |
Clicker Sentences File |
| .clkd |
Clicker Docs File |
| .clkb |
Clicker Books File |
| .clkv |
Clicker Communicator Vocabulary Set File |
| .consis |
Sciral Consistency Document |
| .cosessiondb |
Capture One Session File |
| .cerber3 |
Cerber Ransomware Virus File |