The ClamAV was developed to be an open source (GPL) anti-virus toolkit, especially for e-mail scanning on mail gateways. It provides a number of utilities including a flexible and scalable multi-threaded daemon, a command line scanner and advanced tool for automatic database updates.

The core of the package is an anti-virus engine available in a form of shared library. Copy the virus database packages to the "database" directory inside the main ClamAV folder.

Features:

POSIX compliant, portable

Fast scanning

Detects over 750.000 viruses, worms and trojans, including Microsoft Office macro viruses, mobile malware, and other threats

Built-in bytecode interpreter allows the ClamAV signature writers to create and distribute very complex detection routines and remotely enhance the scanner’s functionality

Scans within archives and compressed (also protects against archive bombs), built-in support includes:

Zip (including SFX)

RAR (including SFX)

7Zip

ARJ (including SFX)

Tar

CPIO

Gzip

Bzip2

MS OLE2

MS Cabinet Files (including SFX)

MS CHM (Compiled HTML)

MS SZDD compression format

BinHex

SIS (SymbianOS packages)

AutoIt

InstallShield

Supports Portable Executable (32/64-bit) & compressed or obfuscated with:

AsPack

UPX

FSG

Petite

PeSpin

NsPack

wwpack32

MEW

Upack

Y0da Cryptor

Supports ELF and Mach-O (both 32- and 64-bit)

Supports almost all mail formats

Support for other special formats includes:

HTML

RTF

PDF

Files encrypted with CryptFF and ScrEnc

uuencode

TNEF (winmail.dat)

Advanced database updater with support for scripted updates, digital signatures and DNS based database version queries