Installation on macOS (Mac OS X)

Below are the steps for installing ClamAV from source on Apple macOS.

Install prerequisites

The easiest way to install prerequisites on macOS is to use Homebrew

     /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
 

     xcode-select --install
 

     brew install pcre2 openssl json-c
 

     brew install valgrind check
 

Note: LLVM is also an optional dependency. LLVM will not provide any additional features, but is an alternative method for executing bytecode signatures versus using the built-in bytecode interpreter. Limited performance testing between LLVM and the bytecode interpreter did not yield conclusive evidence that one is “better” than the other. For the sake of simplicity, it is not recommended to install LLVM.

Download the latest stable release

Extract the source archive

    cd ~/Downloads
    tar xzf clamav-[ver].tar.gz
    cd clamav-[ver].tar.gz

Configure the build

Homebrew installs libraries and applications under /usr/local/Cellar/<app>/<ver>/.

To configure the ClamAV build using our homebrew-installed dependencies, you may need to reference some of them explicitly. Others may be detected automatically.

Typical ./configure usage

*Note: Your Homebrew-installed package version directories may differ slightly.

    ./configure --with-openssl=/usr/local/Cellar/openssl/1.0.2l --with-libjson=yes --enable-check

Once ./configure completes, it will print a summary. Verify that the packages you installed are in fact being detected.

Example configure summary output:

    configure: Summary of detected features follows
                OS          : darwin17.2.0
                pthreads    : yes ()
    configure: Summary of miscellaneous features
                check       : -L/usr/local/lib -lcheck -R/usr/local/lib  (auto)
                fanotify    : no (disabled)
                fdpassing   : 1
                IPv6        : yes
    configure: Summary of optional tools
                clamdtop    : -lncurses (auto)
                milter      : yes (disabled)
                clamsubmit  : yes (libjson-c-dev found at /usr/local), libcurl-devel found at /usr)
    configure: Summary of engine performance features
                release mode: yes
                llvm        : no (disabled)
                mempool     : yes
    configure: Summary of engine detection features
                bzip2       : ok
                zlib        : /usr
                unrar       : yes
                preclass    : yes (libjson-c-dev found at /usr/local)
                pcre        : /usr/local/Cellar/pcre2/10.32
                libmspack   : yes (Internal)
                libxml2     : yes, from /usr
                yara        : yes
                fts         : yes (libc)

If you experience an error wherein configure output claims that gcc is unable to build an executable – please see the Troubleshooting section at the bottom.

Additional popular ./configure options

• --sysconfdir - Install the configuration files to /etc instead of /usr/local/etc:

        ./configure -–sysconfdir=/etc
    

• --prefix - Install ClamAV to a directory other than /usr/local/:
  • Example 1: Install to a local ./install directory.

          ./configure --prefix=`pwd`/install
      

  • Example 2: Install ClamAV locally on an unprivileged shell account.

          ./configure --prefix=$HOME/clamav --disable-clamav
      

• --disable-clamav - Don’t drop super-user priveleges to run freshclam or clamd as the clamav* user.

        ./configure --disable-clamav
    

  *Tip: Using this --disable-clamav means that freshclam and clamd will run with root privleges if invoked using sudo. Running clamd or clamscan as root is not recommended. Instead of using this option, you can configure freshclam or clamd to drop to any other user by:

  • setting the DatabaseOwner option in freshclam.conf and
  • setting the User option in clamd.conf.

Please see the ./configure --help for additional options.

Compile ClamAV

Compile ClamAV with:

    make -j2

If you experience error messages wherein the compiler is unable to find the correct openssl header or library files, you may need to reconfigure and provide explicit header and library paths. See the Troubleshooting section below for details.

Run ClamAV Unit Tests (Optional)

For peace of mind, it can be helpful to run a small suite of unit and system tests.

Run:

    make check

All tests should pass.* Output will look something like this:

        ...
    PASS: check_clamav
    PASS: check_freshclam.sh
    PASS: check_sigtool.sh
    PASS: check_unit_vg.sh
    PASS: check1_clamscan.sh
    PASS: check2_clamd.sh
    PASS: check3_clamd.sh
    PASS: check4_clamd.sh
    PASS: check5_clamd_vg.sh
    PASS: check6_clamd_vg.sh
    SKIP: check7_clamd_hg.sh
    PASS: check8_clamd_hg.sh
    PASS: check9_clamscan_vg.sh
        ...
    ============================================================================
    Testsuite summary for ClamAV 0.100.2
    ============================================================================
    # TOTAL: 13
    # PASS:  12
    # SKIP:  1
    # XFAIL: 0
    # FAIL:  0
    # XPASS: 0
    # ERROR: 0

Notes:

• The *.vg.sh tests will be skipped unless you run make check VG=1.
  • Under macOS, *.vg.sh (valgrind) tests will fail due to false alerts.
  • Valgrind may not be available via Homebrew for the latest version of macOS.
• The check7_clamd.hg.sh (helgrind) is presently disabled and will be skipped.
  • For details, see: the Git commit

If you have a failure or an error in the unit tests, it could be that you are missing one or more of the prerequisites or that there is miss-match in the header files after upgrading to a newer version of macOS. If the latter, please see the Troubleshooting section at the bottom.

If you are investigating a failure, please do the following:

cd unit_tests

Use less to read the log for the failed test. Example:

    less check4_clamd.sh.log`

To submit a bug report regarding unit text failures, please follow these bug reporting steps.

Install ClamAV

Install ClamAV with:

    make install

Tip: If installing to the default or other system-owned directory, you may need to use sudo.

First time set-up

Note: The following instructions assume you used the default install paths (i.e. /usr/local). If you modified the install locations using --prefix or --sysconfdir options, replace /usr/local with your chosen install path.

freshclam config

Before you can use freshclam to download updates, you need to create a freshclam config. A sample config is provided for you.

     cp /usr/local/etc/freshclam.conf.sample /usr/local/etc/freshclam.conf
 

     mkdir /usr/local/share/clamav
 

clamd config (optional)

You can run clamscan without setting the config options for clamd. However, the clamd scanning daemon allows you to use clamdscan to perform faster a-la-carte scans, allows you to run multi-threaded scans, and allows you to use clamav-milter if you want to use ClamAV as a mail filter if you host an email server.

     cp /usr/local/etc/clamd.conf.sample /usr/local/etc/clamd.conf
 

Download / Update the signature database

Before you can run a scan, you’ll need to download the signature databases. Once again, you may need to run with sudo/root privileges.

If you installed to a location in your system PATH:

    freshclam

If you installed to another location:

    /{path}/{to}/{clamav}/bin/freshclam

Users and on user privileges

If you are running freshclam and clamd as root or with sudo, and you did not explicitely configure with --disable-clamav, you will want to ensure that the DatabaseOwner user specified in freshclam.conf owns the database directory so it can download signature udpates.

The user that clamd, clamdscan, and clamscan run as may be the same user, but if it isn’t – it merely needs read access to the database directory.

If you choose to use the default clamav user to run freshclam and clamd, you’ll need to create the clamav group and the clamav user account the first time you install ClamAV.

Prep by identifying an unused group id (gid), and an unused user UniqueID.

This command will display all current group PrimaryGroupIDs:

    dscl . list /Groups PrimaryGroupID | tr -s ' ' | sort -n -t ' ' -k2,2

This command will display all current user UniqueIDs:

    dscl . list /Users UniqueID | tr -s ' ' | sort -n -t ' ' -k2,2

Then, these commands can be used to create the clamav group and clamav user.

    sudo dscl . create /Groups/clamav
    sudo dscl . create /Groups/clamav RealName "Clam Antivirus Group"
    sudo dscl . create /Groups/clamav gid 799           # Ensure this is unique!
    sudo dscl . create /Users/clamav
    sudo dscl . create /Users/clamav RealName "Clam Antivirus User"
    sudo dscl . create /Users/clamav UserShell /bin/false
    sudo dscl . create /Users/clamav UniqueID 599       # Ensure this is unique!
    sudo dscl . create /Users/clamav PrimaryGroupID 799 # Must match the above gid!

Finally, you will want to set user ownership of the database directory. For example:

    sudo chown -R clamav:clamav /usr/local/share/clamav

Usage

You should be all set up to run scans.

Take a look at our usage documentation to learn about how to use ClamAV each of the utilities.

Troubleshooting

Configure – gcc failed to build executable

It is possible that gcc/clang is misconfigured. This is particularly likely after an upgrade to a newer versions of macOS (e.g after an upgrade from macOS High Sierra to macOS Mojave).

Open Terminal, and run the following:

    xcode-select --install

This will download and install xcode developer tools and fix the problem. You will be prompted (in the macOS GUI) to accept the license agreement before it will continue. As a follow on step, you may need to reset the path to Xcode if you have several versions or want the command line tools to run without Xcode.

    xcode-select --switch /Applications/Xcode.app
    xcode-select --switch /Library/Developer/CommandLineTools

Solution shamelessly lifted from apple stackexchange

Make – failed to find correct openssl header or library files

Homebrew provides symlinks in /usr/local/opt to aid in the linking process:

    $ ls -l /usr/local/opt/openssl*

    lrwxr-xr-x  1 gary  admin    24B Aug 21 12:39 /usr/local/opt/openssl@ -> ../Cellar/openssl/1.0.2p
    lrwxr-xr-x  1 gary  admin    24B Aug 21 12:39 /usr/local/opt/openssl@1.0@ -> ../Cellar/openssl/1.0.2p
    lrwxr-xr-x  1 gary  admin    28B Nov 20  2017 /usr/local/opt/openssl@1.1@ -> ../Cellar/openssl@1.1/1.1.0g

If they aren’t automatically detected you may experience issues linking openssl. You can work around this by explicitly listing the include -I and library -L paths.

For example:

    ./configure --with-openssl=/usr/local/Cellar/openssl/1.0.2l --with-libjson=yes --enable-check CPPFLAGS="-I/usr/local/opt/openssl@1.0/include" LDFLAGS="-L/usr/local/opt/openssl@1.0/lib/"

Make check – unit tests failed for seemingly no reason

Similar to the above issue, it is possible for a mismatch in your development header files resulting in a working build that may fail the check test suite.

If you’re seeing one or more failed tests on a stable release of ClamAV on macOS, the following may resolve the issue:

Open Terminal, and run the following:

    sudo installer -pkg /Library/Developer/CommandLineTools/Packages/macOS_SDK_headers_for_macOS_10.14.pkg -target /

Solution shamelessly lifted from the pyenv github issue tracker