ClamAV Antivirus

ClamAV Antivirus

ClamAV is a free, open-source antivirus engine for Linux.

Installation

# Debian/Ubuntu
sudo apt install clamav clamav-daemon

# RHEL/CentOS
sudo dnf install clamav clamav-update clamd

# Update virus definitions
sudo freshclam

Manual Scanning

# Scan directory
clamscan /home/user

# Recursive scan
clamscan -r /var/www

# Scan with output only infected
clamscan -ri /home

# Scan and remove infected
clamscan -ri --remove /path/to/scan

# Scan with summary
clamscan -ri --bell --log=/var/log/clamav-scan.log /home

Daemon Mode

# Start clamd
sudo systemctl start clamav-daemon

# Scan using daemon (faster)
clamdscan /home/user

# Check daemon status
sudo systemctl status clamav-daemon

Automated Scanning

# /etc/cron.daily/clamscan
#!/bin/bash
LOGFILE="/var/log/clamav/daily-scan.log"
clamscan -ri --exclude-dir="^/sys" / > $LOGFILE 2>&1

# Email if infected
INFECTED=$(grep "Infected files:" $LOGFILE | cut -d: -f2 | tr -d ' ')
if [ "$INFECTED" -gt 0 ]; then
    mail -s "ClamAV: Infections Found" [email protected] < $LOGFILE
fi

Definition Updates

# Manual update
sudo freshclam

# Auto-update service
sudo systemctl enable clamav-freshclam
sudo systemctl start clamav-freshclam

# Check definition date
sigtool --info /var/lib/clamav/main.cvd

Scan Options