---
title: ClamAV Installation
---

# ClamAV Installation, Update And Scan Guide.

ClamAV is an open-source antivirus engine designed to detect trojans, viruses, malware, and other malicious threats. This guide provides a step-by-step method to install, update, and configure ClamAV along with an automation script.

## **1. Supported Distributions.**

This script supports the following Linux distributions:

* Ubuntu / Debian
* CentOS 7
* RHEL / CentOS Stream / Rocky Linux / AlmaLinux
* Fedora

## **2. Features of the Script.**
**Automatic** 

* OS detection
* ClamAV and required services.  

**Installs**
* Configures and enables FreshClam (auto virus database updater)
* initial malware scan.  

**Performs**
* Moves infected files to quarantine
* Saves detailed logs under /var/log/clamav/

## **3. Manual Installation Steps.**

* **On Debian / Ubuntu**

```bash
sudo apt update
sudo apt install -y clamav clamav-daemon. 
```

* **On CentOS 7**

```bash
sudo yum install -y epel-release
sudo yum install -y clamav clamav-update
```

* **On RHEL / Rocky Linux / AlmaLinux / Fedora**

```bash
sudo dnf install -y epel-release
sudo dnf install -y clamav clamav-update
```

## **4. Update Virus Database.**

Before scanning, always update ClamAV virus definitions:

```bash 
sudo systemctl stop clamav-freshclam
sudo freshclam
sudo systemctl start clamav-freshclam
```

## **5. Running a Scan**

**Quick Scan**

```bash 
clamscan -r /home
```
**Full System Scan (excluding system directories)**

```bash
sudo clamscan -r -i \
  --exclude-dir="^/sys" \
  --exclude-dir="^/proc" \
  --exclude-dir="^/dev" \
  --move=/var/quarantine \
  --log=/var/log/clamav/scan.log /
```

## **6. Automation Script**

Save the following as clamav-installer.sh

```bash
#!/bin/bash
# ==========================================================
# ClamAV Auto Installer, Updater, and Scanner
# Works on: Ubuntu, Debian, CentOS, RHEL, Rocky, AlmaLinux, Fedora
# ==========================================================

LOGDIR="/var/log/clamav"
SCANLOG="$LOGDIR/initial-scan.log"
QUARANTINE="/var/quarantine"

# Ensure log and quarantine directories exist
sudo mkdir -p "$LOGDIR" "$QUARANTINE"

echo "[+] Detecting OS..."
if [ -f /etc/debian_version ]; then
    echo "[+] Debian/Ubuntu detected"
    sudo apt update
    sudo apt install -y clamav clamav-daemon
elif [ -f /etc/redhat-release ]; then
    if grep -q "CentOS Linux release 7" /etc/redhat-release; then
        echo "[+] CentOS 7 detected"
        sudo yum install -y epel-release
        sudo yum install -y clamav clamav-update
    else
        echo "[+] RHEL / CentOS Stream / Fedora detected"
        sudo dnf install -y epel-release
        sudo dnf install -y clamav clamav-update
    fi
else
    echo "[!] Unsupported distribution"
    exit 1
fi

echo "[+] Enabling FreshClam auto-updater..."
sudo systemctl enable clamav-freshclam
sudo systemctl start clamav-freshclam

echo "[+] Updating virus database..."
sudo systemctl stop clamav-freshclam
sudo freshclam
sudo systemctl start clamav-freshclam

echo "[+] Running initial malware scan..."
sudo clamscan -r -i \
    --exclude-dir="^/sys" \
    --exclude-dir="^/proc" \
    --exclude-dir="^/dev" \
    --move="$QUARANTINE" \
    --log="$SCANLOG" /

echo "[+] Scan complete."
echo " → Log file: $SCANLOG"
echo " → Quarantine dir: $QUARANTINE"
```

## **7. Usage Instructions**

* **Save the script:**

```bash 
nano clamav-installer.sh
```

(Paste the code above, then save and exit CTRL+O, CTRL+X)

* **Make it executable**

```bash
chmod +x clamav-installer.sh
```

* **Run the script:**

```bash
./clamav-installer.sh
```

## **8. Output & Logs**

* **Logs are stored in:**

```bash
/var/log/clamav/initial-scan.log
```

* **Infected files are moved to:**

```bash
/var/quarantine
```

## **9. Schedule Regular Scans (Optional).**

**Create a cron job for daily scans:**

* **Open the root crontab:**

```bash
sudo crontab -e
```

* **Add this line at the bottom:**

```bash
0 2 * * * /usr/bin/clamscan -r -i --move=/var/quarantine --log=/var/log/clamav/daily-scan.log /
```



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