You can view the documentation below, or browse our GitHub Repository, where you can contribute to user manual and FAQ.

Upgrading ClamAV

ClamAV from Packages

If you installed from a package, we suggest you find the approved package from your distro provider and install that. The ClamAV team does not maintain individual packages for every distribution build. If there are no new packages, you have three options:

  • Wait
  • Build ClamAV Package
  • Install ClamAV From Source

Install ClamAV From Source

If you installed from sources, first uninstall the old version:


sudo make uninstall

Compile and install the new one: see Installing ClamAV

Depending on your installation method, you might want to backup configuration (located in /usr/local/etc by default) and signature database (located in /usr/local/share/clamav by default). Don’t forget to restore backups before starting up updated ClamAV.

Backup your database signature (located in /usr/local/share/clamav by default) before upgrading to newer ClamAV version. Restore the backed up database signature before running the updated version. This is to avoid getting the /usr/local/share/clamav not locked error message when doing freshclam.

Webmin and Yum

To obtain a new version:

yum list clamav

yum update clamav

If everything updated properly, run freshclam to update your signature database.

What does “WARNING: Current functionality level = 1, required = 2” mean?

The functionality level of the database determines which scanner engine version is required to use all of its signatures. If you don’t upgrade immediately you will be missing the latest viruses.

What does “Your ClamAV installation is OUTDATED” mean?

You’ll get this message whenever a new version of ClamAV is released. In order to detect all the latest viruses, it’s not enough to keep your database up to date. You also need to run the latest version of the scanner. You can download the sources of the latest release from our website. If you are afraid to break something while upgrading, use the precompiled packages for your operating system/distribution. Remember: running the latest stable release also improves stability.

I upgraded to the latest stable version but I still get the message “Your ClamAV installation is OUTDATED”, why?

Make sure there is really only one version of ClamAV installed on your system:

$ whereis freshclam

$ whereis clamscan

Also make sure that you haven’t got old libraries (*) lying around your filesystem. You can verify it using:

$ ldd $(which freshclam)

What does “Malformed hexstring: This ClamAV version has reached End of Life” mean?

Please refer to: eol-clamav

How do I verify the integrity of ClamAV sources?

Using GnuPG you can easily verify the authenticity of your stable release downloads by using the following method: Download the Talos PGP public key from the VRT labs site. Import the key into your local public keyring:

$ gpg --import vrt.gpg

Download the stable release AND the corresponding .sig file to the same directory. Verify that the stable release download is signed with the Talos PGP public key:

$ gpg --verify clamav-X.XX.tar.gz.sig

Please note that the resulting output should look like the following:

    gpg: Signature made Wed Jan 24 19:31:26 2018 EST
    gpg:                using RSA key F13F9E16BCA5BFAD
    gpg: Good signature from "Talos (Talos, Cisco Systems Inc.) [email address]" [unknown]

For other PGP implementation, please refer to their manual.

Where can I get the latest release, beta, or release candidate of ClamAV?

Visit the source download page.

Is my compiler/hardware/operating system supported by ClamAV?

ClamAV supports a wide variety of compilers, hardware and operating systems. Our core compiler is gcc with Linux on 32 and 64 bit Intel platforms, though we also test using other compilers, including Sun’s C compiler, Microsoft’s Visual Studio, Intel’s C compiler, LLVM/Clang, and others. To date we have only found one compiler that we do not support, GCC version 4.0.0 to 4.0.1 inclusive. We have found that version of the compiler produces incorrect code on all of the platforms and operating systems on which we have tested it. ClamAV will not work using that compiler and you MUST switch to an alternative, such as GCC3.4 or GCC4.1.

Please contact your vendor for further information. Please refer to gcc’s bugzilla for further information. More information about this bug is also available in our bugzilla.

Our configure scripts will detect if your compiler is affected by this bug and refuse to generate a non working binary with the following error message:

    your compiler has gcc PR26763-2 bug, use a different compiler