Ozone Depleting Chemicals CFCs The destruction of ozone is accelerated by certain trace gases containing nitrogen, hydrogen, bromine, and chlorine. These are referred to as ozone depletion chemicals.
YAC (which stands for Yet Another Cleaner) is a company developing not only registry cleaners but all sorts of system utilities and security tools. And one of their best creations is the YAC Virus Removal Tool (which removes viruses, that must be clear).
A file with the AVC file extension is most likely a Kaspersky Virus Database file, which the Kaspersky antivirus software uses to store information regarding updates to the program. They're normally named with a file update number, something like base008.avc.