You can view the documentation below, or browse our GitHub Repository, where you can contribute to user manual and FAQ.
General | Installing ClamAV | How to Report A Bug | Miscellaneous FAQ | ClamAV Virus Database FAQ | End of Life Policy (EOL) | Potentially Unwanted Applications (PUA) | Mailing Lists FAQ | Troubleshooting FAQ | Safebrowsing | Upgrading ClamAV | ClamAV on Microsoft Windows FAQ | Which Version of ClamAV should I use? | Uninstalling ClamAV | ClamAV Overview | Interpreting Scan Alerts FAQ | Freshclam FAQ | How do I ignore a ClamAV signature?
Manual | Clam AntiVirus User Manual
Manual | UserManual | Installing ClamAV on Unix / Linux / macOS from Source | Installing ClamAV on Windows | Introduction | LibClamAV | On-Access Scanning | Creating signatures for ClamAV | Usage | ClamAV Development | Contribute
Manual | UserManual | Installation-Unix | Installation on Debian and Ubuntu Linux Distributions | Installation on macOS (Mac OS X) | Installation on Redhat and CentOS Linux Distributions
Manual | UserManual | Signatures | Trusted and Revoked Certificates | Body-based Signature Content Format | Bytecode Signatures | Signatures based on container metadata | Database Info | Dynamic Configuration (DCONF) | Passwords for archive files \[experimental\] | Extended signature format | File Type Magic | ClamAV File Types | Functionality Levels (FLEVELs) | File hash signatures | Logical signatures | PhishSigs | Using YARA rules in ClamAV | Allow list databases
Manual | UserManual | Usage | Configuration | Scanning | Signature Testing and Management
Additional | Microsoft Authenticode Signature Verification | Private Local Mirrors
If you are running ClamAV 0.7x please upgrade now.
If you are running ClamAV 0.8x or later, you can check for database update as often as 4 times per hour provided that you have the following options in freshclam.conf
:
DNSDatabaseInfo current.cvd.clamav.net
DatabaseMirror database.clamav.net
Please run clamscan with the --detect-broken
option. Also check that freshclam and clamscan are using the same path for storing/reading the database.
Our virus database is kept up to date with the help of the community. Whenever you find a new virus which is not detected by ClamAV you should complete this form. The virusdb team will review your submission and update the database if necessary. Before submitting a new sample: - check that the value of DatabaseDirectory, in both clamd.conf and freshclam.conf, is the same - and update your database by running freshclam to ensure you’ve scanned it with the latest virus database.
ClamAV comes with freshclam, a tool which periodically checks for new database releases and keeps your database up to date.
There is a problem with your DNS server. Please check the entries in /etc/resolv.conf
and verify that you can resolve the TXT record manually:
$ host -t txt current.cvd.clamav.net
If you can’t, it means your network is broken. You’ll be still able to download the updates, but you’ll waste a lot of bandwidth checking for updates.
Either your dns servers are not working or you are blocking port 53/tcp. You should manually check that you can resolve hostnames with:
$ host database.clamav.net
If it doesn’t work, check your dns settings in /etc/resolv.conf
. If it works, check that you can receive dns answers longer than 512 bytes, e.g. check that your firewall is not blocking packets which originate from port 53/tcp. An easy way to find it out is:
$ dig @ns1.clamav.net db.us.big.clamav.net
Try to download daily.cvd
with curl, wget, or lynx from the same machine that is running freshclam. Future versions of freshclam will provide a better way to deal with this.
mirrors.dat
is used by freshclam to keep track of broken mirrors. It avoids the unnecessary delays caused by trying to download a CVD update from a mirror which failed multiple times during the last 24 hours.
Sure, you can find more details on our Private Local Mirror page.
If you want to take advantage of incremental updates, install a proxy server and then configure your freshclam clients to use it (watch for the HTTPProxyServer parameter in man freshclam.conf).
The second possible solution is to:
Configure a local webserver on one of your machines (say machine1.mylan)
Let freshclam download the *.cvd
files from http://database.clamav.net to the webserver’s DocumentRoot.
Finally, change freshclam.conf on your clients so that it includes:
DatabaseMirror machine1.mylan
ScriptedUpdates off
First the database will be downloaded to the local webserver and then the other clients on the network will update their copy of the database from it.
Important: For this to work, you have to add ScriptedUpdates off
on all of your machines!
No problem, save your own signatures in a text file with the appropriate extension (see our signature writing documentation for more information). Put the signature file in the same directory where the .cvd
files are located. ClamAV will load it after the official .cvd
files. You do not need to sign the .db
file.
Yes, the virusdb can be downloaded from the Latest releases section on our home page.
current.cvd.clamav.net has got only a TXT record, not a type A record! Try this command:
$ host -t txt current.cvd.clamav.net
Please note that some not RFC compliant DNS servers (namely the one shipped with the Alcatel (now Thomson) SpeedTouch 510 modem) can’t resolve TXT record. If that’s the case, please recompile ClamAV with the flag --enable-dns-fix
.
You will need to edit the freshclam.conf.example
file located in /usr/local/etc
. Once that is done, you will need to run a sudo freshclam
to download the signatures. You will need to run the command to update signatures often so that ClamAV has the most up to date signatures.