Clam AntiVirus is an open source (GPL) anti-virus toolkit for UNIX. It provides a number of utilities including a flexible and scalable multi-threaded daemon, a command line scanner and advanced tool for automatic database updates. Because ClamAV's main use is on file/mail servers for [Windows](../windows/Windows.md) desktops, it primarily detects [Windows](../windows/Windows.md) viruses and malware with its built-in signatures.
## Usage
### Updating database
Update the virus definitions with:
```shell
freshclam
```
The database files are saved in:
```
/var/lib/clamav/daily.cvd
/var/lib/clamav/main.cvd
/var/lib/clamav/bytecode.cvd
```
Start/Enable`clamav-freshclam.service`so that the virus definitions are kept recent.
> - You will need to run`freshclam`before starting the service for the first time or you will run into trouble/errors which will prevent ClamAV from starting correctly.
> - The daemon is not needed if you only want to perform stand-alone scans.
The service is called`clamav-daemon.service`.
### Scanning for viruses
`clamscan`can be used to scan certain files, home directories, or an entire system:
If you would like`clamscan`to remove the infected file add to the command the`--remove`option, or you can use`--move=/dir`to quarantine them.
You may also want`clamscan`to scan larger files. In this case, append the options`--max-filesize=4000M`and`--max-scansize=4000M`to the command. '4000M' is the largest possible value, and may be lowered as necessary.
