When running a Linux server for personal websites, memory usage becomes crucial - especially on smaller instances. The ClamAV daemon (clamd) consuming 2GB RAM (5% of your total) is significant for lightweight deployments. Let's examine scenarios where disabling might be acceptable:

# Check current clamd memory usage
ps aux | grep clamd
# Typical output showing resident memory:
# clamav   12345  2.3  5.0 2123456 2048000 ?      Ssl  May10  10:25 /usr/sbin/clamd

Your email workflow presents two attack surfaces:

• POP3 account fetching (Gmail-mediated)
• Website email parsing for attachments

The attachment processing script is particularly vulnerable. Consider this Python example that would benefit from AV scanning:

import email
import os

def process_attachments(raw_email):
    msg = email.message_from_string(raw_email)
    for part in msg.walk():
        if part.get_content_maintype() == 'multipart':
            continue
        if part.get('Content-Disposition') is None:
            continue
            
        filename = part.get_filename()
        if filename:
            filepath = os.path.join('/attachments', filename)
            with open(filepath, 'wb') as f:
                f.write(part.get_payload(decode=True))
            # Missing security check here!

If disabling clamd, implement these compensatory measures:

# 1. Restrict uploaded file types in nginx
location ~* \.(php|js|exe|bat)$ {
    deny all;
}

# 2. Implement filesystem quarantine
mkdir -p /uploads/quarantine
chmod 1733 /uploads/quarantine  # Sticky bit + no read/write for others

Replace continuous scanning with periodic checks:

# Cron job for nightly scans
0 3 * * * /usr/bin/freshclam && /usr/bin/clamscan -r -i /var/www /opt/uploads

For critical systems, consider lightweight alternatives like rkhunter for rootkit detection:

sudo apt install rkhunter
sudo rkhunter --update
sudo rkhunter --check

ClamAV's daemon (clamd) provides real-time malware scanning for files processed by your web applications. While consuming 2GB (5% of memory) might seem significant, this memory allocation actively protects against:

• Malicious file uploads through web forms
• Infected email attachments processed by your POP3 service
• Potential compromise of image uploads from email parsing

Given your described environment with:

// Sample configuration for email processing
$mail_parser->setVirusScan(true); // Currently relying on clamd
$mail_parser->setAttachmentPath('/var/www/uploads/');

The primary risks of disabling clamd would be:

1. Unchecked malicious files reaching your filesystem
2. Potential PHP mail script vulnerabilities (e.g., if using mail() with unchecked inputs)
3. Infected images being served to users

Instead of complete removal, consider these optimizations:

# In clamd.conf:
MaxThreads 2          # Default is often too high
MaxScanSize 10M       # Adjust based on your typical files
StreamMaxLength 2M    # For email attachments

For non-critical applications, implement scanning only where needed:

# Example PHP upload handling with selective scanning
if ($_FILES['upload']['type'] == 'application/pdf') {
    exec('/usr/bin/clamdscan --no-summary '.escapeshellarg($_FILES['upload']['tmp_name']), $output, $return);
    if ($return !== 0) {
        unlink($_FILES['upload']['tmp_name']);
        die("Malicious file detected");
    }
}

If you choose to disable clamd, implement these safeguards:

# Cron job for periodic scanning
0 3 * * * /usr/bin/freshclam && /usr/bin/clamscan -r --bell -i /var/www /home