Security

Basic Linux server protection includes several mandatory steps: disabling root login, using SSH keys instead of passwords, changing the default SSH port, installing fail2ban to block brute-force attacks, configuring a firewall (UFW/iptables), and keeping the system updated. It's also important to monitor logs for suspicious activity and restrict access to services to only the necessary IP addresses.

These are just the basics — see the full 15-point checklist via the link.

Much safer than an openly exposed port. But verify that VPN is really the only path in — sometimes parallel public IP access remains "just in case."

Yes. A VPN and firewall block external access, but they don't guarantee protection against insider threats, compromised accounts, or misconfigured rules. fail2ban adds another layer of defense by automatically blocking IPs after several failed login attempts, reducing brute-force risk even inside an already protected perimeter. A layered 'defense in depth' approach is always more reliable than a single line of defense.

The most common threats are phishing (credential theft via fake emails), ransomware (data encryption with a ransom demand), and DDoS attacks (service overload). Small and medium businesses often fall victim precisely because they assume they're 'not interesting enough' for attackers, while automated attacks don't discriminate by company size.

The minimum set of measures includes: regular data backups (with tested recovery), training employees to spot phishing, implementing two-factor authentication, keeping software updated, and limiting access rights on a least-privilege basis. These steps don't require major investment but significantly reduce the risk of a successful attack.

Signs of phishing include: an unusual sender address (similar but not identical to the real one), urgency and pressure ('urgently restore access'), design or text errors, links leading to an unexpected domain, and requests to enter a password or card details outside the usual interface. In 2026, phishing is becoming more sophisticated with AI-generated emails and even deepfake voice calls, so it's wise to verify requests through a separate communication channel.

SPF, DKIM, and DMARC are DNS records that confirm an email genuinely came from your domain rather than from an attacker spoofing the sender address. SPF verifies which servers are authorized to send mail on behalf of the domain, DKIM adds a digital signature to verify message integrity, and DMARC defines what to do with emails that fail these checks. Together they make it significantly harder to spoof corporate email and protect your domain's reputation.

Signs of camera compromise include: unusual network load or increased traffic from the camera, sluggish performance or random reboots, settings changed without your input, suspicious users in the P2P access list, and vendor warnings about vulnerabilities in your model. Mass attacks on Dahua and EZ-IP cameras via P2P and known CVEs show that outdated firmware and weak passwords are the main causes of infection.

The first step is to disconnect the camera from the internet (keeping local access if needed), reset it to factory settings, update the firmware to the latest version, and set a new strong password. Next, disable the P2P feature if it's not critically needed, review the list of users with access, and restrict camera access via VPN or an internal network instead of direct internet exposure.

No, antivirus is just one piece of the puzzle — usually effective against known threats but not against phishing, social engineering, web application vulnerabilities, or misconfigured servers. Comprehensive business protection requires a combination of technical measures (firewall, backups, system updates), organizational measures (staff training, access policies), and network activity monitoring.