Scanning for Viruses


Even though Windows systems get the most attention from virus writers, other platforms can still act as sources of infections. Compromised Web sites and email servers could send viruses on to unsuspecting client systems.

ClamAV ( www.clamav.net) is a free high-quality virus-scanning tool for Unix systems; you can use it to make sure your system isn't storing any known viruses, worms, or Trojans. Because Unix viruses are rare enough to be almost nonexistent, ClamAV is usually used on Unix mail servers to ensure that Windows viruses don't make it through to the Windows client systems receiving their email from the Unix server.

Tip

  • As of this writing (shortly after the release of Fedora Core 3), ClamAV couldn't be built on Fedora Core, and there wasn't a binary package available. Keep on eye on the ClamAV Web site ( www.clamav.net) and your favorite Fedora package sites for more information.


To install ClamAV (FreeBSD)

1.

Log in as root.

You could also use the su command to become root if you're already logged in.

2.

cd /usr/ports/security/clamav

ClamAV is included in the ports collection.

3.

make install clean

The "Options for clamav" dialog is displayed (Figure 4.2).

Figure 4.2. Sometimes optional packages are included with FreeBSD's ports; this version of ClamAV can work with the Milter email interface.


4.

Press Enter to select the MILTER option (it adds email-filtering capabilities) in the "Options for clamav" dialog.

5.

Press Tab, then Enter to dismiss the "Options for clamav" dialog and continue with the installation.

The installer downloads the source code, then builds and installs ClamAV and its dependencies.

To install ClamAV (Cygwin):

1.

Launch the Cygwin installer (setup.exe); if you didn't keep this handy, refer to Appendix D for download instructions.

2.

In the installer, click the Next button until you reach the package list.

3.

Expand the Utils category by clicking the + (plus) sign next to the category name.

4.

Drag the Cygwin Setup window's lower-right corner to expand the window so that you can find the clamav enTRy.

5.

Click the circle-arrow icon in the clamav row so that Skip changes to a version number (Figure 4.3). This is the version that will be installed.

Figure 4.3. Finding ClamAV in the Cygwin Setup program.


6.

Click the installer's Next button. Cygwin Setup downloads and installs clamav and any updated versions of packages you've already installed.

7.

Click Finish to exit the installer.

To install ClamAV (Mac OS X):

1.

Open a Mac OS X Terminal window.

2.

sudo fink install clamav

Tell Fink to download, build, and install ClamAV.

3.

At the Password prompt, type your password, and then press Enter to continue.

4.

If prompted to download the latest virus definitions, press Enter.

To update the ClamAV signature database:

1.

Log in as root, or use the su command to become root if you're already logged in.

2.

freshclam

The freshclam command examines your current ClamAV databases and downloads new virus signatures if there are any available.

To scan your system for viruses with ClamAV:

1.

Log in as root, or use the su command to become root if you're already logged in.

2.

clamscan -r -i path

Scan the specified path (which can be a file, or can be a directory if you also use the -r option) for viruses. The -i option tells clamscan to list only infected files instead of every file that gets scanned.



    Unix Advanced. Visual QuickPro Guide
    Unix Advanced: Visual QuickPro Guide
    ISBN: 0321205499
    EAN: 2147483647
    Year: 2003
    Pages: 116

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