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freshclam.conf - Configuration file for Clam AntiVirus database update
The file freshclam.conf configures the Clam AntiVirus Database Updater,
The file consists of comments and options with arguments. Each line which starts
with a hash (#) symbol is ignored by the parser. Options and arguments
are case sensitive and of the form Option Argument. The arguments are
of the following types:
- Boolean value (yes/no or true/false or 1/0).
- String without blank characters.
- Size in bytes. You can use 'M' or 'm' modifiers for megabytes and 'K' or
'k' for kilobytes.
- Unsigned integer.
When an option is not used (hashed or doesn't exist in the configuration file)
freshclam takes a default action.
- If this option is set freshclam will not run.
- LogFileMaxSize SIZE
- Limit the size of the log file. The logger will be automatically disabled
if the file is greater than SIZE. Value of 0 disables the limit.
- LogTime BOOL
- Log time with each message.
- LogSyslog BOOL
- Enable logging to Syslog. May be used in combination with UpdateLogFile.
- LogFacility STRING
- Specify the type of syslog messages - please refer to 'man syslog' for
- LogVerbose BOOL
- Enable verbose logging.
- LogRotate BOOL
- Rotate log file. Requires LogFileMaxSize option set prior to this option.
- PidFile STRING
- This option allows you to save the process identifier of the daemon to a
file specified in the argument.
- DatabaseDirectory STRING
- Path to a directory containing database files.
- Foreground BOOL
- Don't fork into background.
- Debug BOOL
- Enable debug messages in libclamav.
- UpdateLogFile STRING
- Enable logging to a specified file. Highly recommended.
- DatabaseOwner STRING
- When started by root, drop privileges to a specified user.
- Checks NUMBER
- Number of database checks per day.
- DNSDatabaseInfo STRING
- Use DNS to verify the virus database version. Freshclam uses DNS TXT
records to verify the versions of the database and software itself. With
this directive you can change the database verification domain.
WARNING: Please don't change it unless you're configuring freshclam
to use your own database verification domain.
Default: enabled, pointing to current.cvd.clamav.net
- DatabaseMirror STRING
- DatabaseMirror specifies to which mirror(s) freshclam should connect. You
should have at least one entries: database.clamav.net. Now that CloudFlare
is being used as our Content Delivery Network (CDN), this one domain name
works world-wide to direct freshclam to the closest geographic endpoint.
- PrivateMirror STR
- This option allows you to easily point freshclam to private mirrors. If
PrivateMirror is set, freshclam does not attempt to use DNS to determine
whether its databases are out-of-date, instead it will use the
If-Modified-Since request or directly check the headers of the remote
database files. For each database, freshclam first attempts to download
the CLD file. If that fails, it tries to download the CVD file. This
option overrides DatabaseMirror, DNSDatabaseInfo and ScriptedUpdates. It
can be used multiple times to provide fall-back mirrors.
- MaxAttempts NUMBER
- How many attempts (per mirror) to make before giving up.
Default: 3 (per mirror)
- ScriptedUpdates BOOL
- With this option you can control scripted updates. It's highly recommended
to keep it enabled.
- TestDatabases BOOL
- With this option enabled, freshclam will attempt to load new databases
into memory to make sure they are properly handled by libclamav before
replacing the old ones.
- CompressLocalDatabase BOOL
- By default freshclam will keep the local databases (.cld) uncompressed to
make their handling faster. With this option you can enable the
compression; the change will take effect with the next database update.
- ExtraDatabase STRING
- Download an additional 3rd party signature database distributed through
the ClamAV mirrors. This option can be used multiple times.
- ExcludeDatabase STRING
- Exclude a standard signature database (opt-out). This option can be used
- DatabaseCustomURL STRING
- With this option you can provide custom sources for database files. This
option can be used multiple times. Support for:
http(s)://, ftp(s)://, or file:// Example usage:
- HTTPProxyServer STR, HTTPProxyPort NUMBER
- Use given proxy server and TCP port for database downloads. The
HTTPProxyServer may be prefixed with [scheme]:// to specify which kind of
proxy is used.
http:// HTTP Proxy. Default when no scheme or proxy type is specified.
https:// HTTPS Proxy. (Added in 7.52.0 for OpenSSL, GnuTLS and NSS)
socks4:// SOCKS4 Proxy.
socks4a:// SOCKS4a Proxy. Proxy resolves URL hostname.
socks5:// SOCKS5 Proxy.
socks5h:// SOCKS5 Proxy. Proxy resolves URL hostname.
- HTTPProxyUsername STR,HTTPProxyPassword STRING
- Proxy usage is authenticated through given username and password.
- HTTPUserAgent STRING
- If your servers are behind a firewall/proxy which applies User-Agent
filtering, you can use this option to force the use of a different
- NotifyClamd STRING
- Notify a running clamd(8) to reload its database after a download has
occurred. The path for clamd.conf file must be provided.
Default: The default is to not notify clamd. See clamd.conf(5)'s option
SelfCheck for how clamd(8) handles database updates in this case.
- OnUpdateExecute STRING
- Execute this command after the database has been successfully updated.
- OnErrorExecute STRING
- Execute this command after a database update has failed.
- OnOutdatedExecute STRING
- Execute this command when freshclam reports outdated version. In the
command string %v will be replaced by the new version number.
- LocalIPAddress IP
- Use IP as client address for downloading databases. Useful for
multi homed systems.
Default: Use OS'es default outgoing IP address.
- ConnectTimeout NUMBER
- Timeout in seconds when connecting to database server.
- ReceiveTimeout NUMBER
- Timeout in seconds when reading from database server. 0 means no timeout.
- SafeBrowsing BOOL
- This option enables support for Google Safe Browsing. When activated for
the first time, freshclam will download a new database file
(safebrowsing.cvd) which will be automatically loaded by clamd and
clamscan during the next reload, provided that the heuristic phishing
detection is turned on. This database includes information about websites
that may be phishing sites or possible sources of malware. When using this
option, it's mandatory to run freshclam at least every 30 minutes.
Freshclam uses the ClamAV's mirror infrastructure to distribute the
database and its updates but all the contents are provided under Google's
https://www.clamav.net/documents/safebrowsing for more information.
- Bytecode BOOL
- This option enables downloading of bytecode.cvd, which includes additional
detection mechanisms and improvements to the ClamAV engine.
Thomas Lamy <firstname.lastname@example.org>, Tomasz Kojm
<email@example.com>, Kevin Lin <firstname.lastname@example.org>