by The Computing Australia Group | Simple Tips to Avoid
Computer Viruses
Cyber-threats evolve fast, but avoiding a computer virus mostly comes down to nailing the basics of staying safe are stable and practical. This guide modernises the classic “don’t click strange links” advice with a 2025-ready playbook for home users, students, and small businesses. You’ll get a clear prevention checklist, step-by-step incident actions, and smart tools that make security easier without turning you into a full-time IT admin.
TL;DR: Your Quick Hardening Checklist
- Keep your OS, browser, and apps patched with auto-updates on.
- Use a reputable antivirus/EDR and let it update itself daily.
- Turn on firewall (built-in is fine) and DNS filtering (e.g., via your security suite).
- Enable multi-factor authentication (MFA) on email and key accounts.
- Use a password manager and unique passwords.
- Back up files using a 3-2-1 strategy (local + cloud; test restores).
- Be suspicious of attachments and links, even from known contacts.
- Disable macros by default (Office/Docs) and restrict file-type execution.
- Remove unused software; restrict admin rights; run daily life as a standard user.
- Secure your Wi-Fi (WPA3 if available; strong passphrase); avoid unknown USBs.
Why a Computer Virus Still Matters in a Post-Antivirus World
Today’s “viruses” are part of a larger malware ecosystem-ransomware, info-stealers, trojans, worms, cryptominers, and file-less attacks abusing legitimate tools. Attackers target what’s most profitable: your data, your identity, and your access to online services. While good antivirus is essential, your habits and configuration are what tip the scales.
1) Keep Software Updated (and Let It Update Itself)
What to update:
- Operating system (Windows/macOS/Linux/ChromeOS)
- Browsers (Chrome, Edge, Firefox, Safari)
- Browser extensions (audit and prune monthly)
- Office suites (Microsoft 365, Google Workspace add-ons)
- PDF readers, media players, Java, Python runtimes, game launchers
- Firmware (router/Wi-Fi access point; laptop BIOS/UEFI; NAS devices)
Best practices:
- Turn on automatic updates everywhere possible.
- Set a weekly “update window” to catch anything that needs manual approval.
- Uninstall software you don’t use-fewer apps = fewer vulnerabilities.
2) Antivirus vs. EDR: Choosing the Right Protection
Antivirus (AV) detects known bad files and suspicious behaviours. EDR (Endpoint Detection & Response) adds continuous monitoring, sandboxing, and rapid rollback/containment-great for ransomware and advanced threats.
Home/SOHO minimum:
- A reputable AV that includes web protection (URL/attachment filtering), ransomware shields, and email scanning.
- Real-time protection ON, daily updates ON, weekly full scans SCHEDULED.
Small business upgrade:
- Managed EDR or a business security suite with centralised console, device isolation, and automated remediation.
- Policy enforcement (e.g., block suspicious scripts, restrict USB storage).
Tip: Whatever you pick, keep it current and don’t run two real time AV engines at once-they can conflict.
3) Firewalls & Network Hygiene: Your First Line of Defence
- OS Firewall: Leave it on. Create explicit allowances only for apps you trust.
- Router Firewall/NAT: Ensure it’s enabled; turn off UPnP if you don’t need it.
- Guest Wi-Fi: Separate network for visitors and IoT devices (cameras, doorbells).
- DNS Filtering: Many suites or DNS services block known malicious domains early.
Wi-Fi setup tips:
- Use WPA3 (or WPA2-AES if WPA3 not available).
- Long passphrase (at least 14 characters).
- Rename your SSID to something non-identifying (avoid your name/address).
- Update router firmware twice a year (or enable auto-updates).
4) Browser & Email Hygiene (Where Most Threats Start)
Safer browsing defaults:
- Use modern browsers with HTTPS-Only Mode if available.
- Limit extensions; only keep those you truly need from trusted developers.
- Turn on enhanced phishing/malware protection in your browser settings.
- Consider enabling a built-in tracker blocker or your suite’s web shield.
Email & messaging:
- Treat links and attachments as guilty until proven innocent.
- Verify unexpected emails via a separate channel (call/text) before opening files.
- Be alert for look-alike domains and typosquats (e.g., “micr0soft”).
- Don’t forward suspicious files to colleagues-report them to IT/security.
Dangerous file types to treat with extra caution: .exe, .msi, .bat, .cmd, .js, .vbs, .ps1, .scr, .hta, and even Office documents with macros (.docm, .xlsm). Keep Office macros disabled by default and only enable signed, trusted ones.
5) Least-Privilege Living: Use a Standard Account Daily
Running as admin makes it easier for malware to install silently.
- Create a standard user for daily use.
- Keep an administrator account only for software installs or system changes.
- Turn on User Account Control (UAC) and Gatekeeper (macOS) at their recommended levels.
- On Windows, consider SmartScreen “Warn” at minimum; “Block” for unknown apps is even better.
6) Passwords, MFA, and the Identity Layer
Strong device security doesn’t help if attackers simply log in as you.
- Use a password manager to generate and store unique passwords per site.
- Turn on MFA (authenticator app or hardware key preferred over SMS) for email, banking, password manager, and cloud storage.
- Rotate passwords only when you suspect compromise-or when a site is breached.
- Watch for consent phishing-malicious apps requesting access to your account data. Review third-party app permissions quarterly.
7) Backups: Your Ransomware Insurance
Follow the 3-2-1 rule:
- 3 copies of your data (1 working, 2 backups)
- 2 different media (e.g., external drive + cloud)
- 1 copy off-site (cloud backup counts)
Essentials:
- Automate daily or weekly backups.
- Encrypt your backups.
- Test restores quarterly-proof beats hope.
- Keep at least one backup offline/immutable to defeat ransomware.
8) Smart Use of External Devices & Public Networks
- USB risks: Disable autorun; consider read-only adapters. Never plug found USBs.
- Public Wi-Fi: Avoid accessing sensitive accounts; if you must, use a trusted VPN and verify you’re on the correct network name.
- Shared computers: Use web apps in private/incognito mode and log out fully.
9) Platform-Specific Tips
Essentials:
- Turn on Microsoft Defender features (SmartScreen, Exploit Protection, Controlled Folder Access if compatible).
- Keep PowerShell constrained for regular users; only admins should run scripts.
- Consider Windows Sandbox (Pro/Enterprise) for opening untrusted files safely.
macOS
- Keep Gatekeeper on; only allow App Store and identified developers.
- Use XProtect and Malware Removal Tool updates (automatic).
- Beware “permission bloat”-audit apps with Full Disk Access and Screen Recording.
Mobile (iOS/Android)
- Update promptly; install apps only from the official store.
- Review app permissions (location, contacts, files); revoke anything unnecessary.
- Don’t sideload APKs; turn off “Install unknown apps.”
10) Recognise the Red Flags of Infection
- Sudden slowdown, crashes, or frequent fan spin-ups
- Pop-ups or new toolbars/extensions you didn’t install
- Browser redirects and search hijacking
- Files renamed or encrypted, ransom notes appearing
- Antivirus disabled or can’t launch Task Manager/Activity Monitor
- Outbound traffic spikes; contacts receive strange emails from you
11) What to Do If You Suspect a Virus (Step-by-Step)
1. Disconnect from the internet (turn off Wi-Fi; unplug Ethernet).
2. Preserve evidence: Don’t reboot repeatedly (can destroy volatile clues).
3. Run a full scan with your AV/EDR. Quarantine anything flagged.
5. Change key passwords (email, bank, password manager) from a different, clean device ; enable or re-check MFA.
6. Check recent logins for your major accounts (e.g., email, cloud drive) and sign out of all sessions.
7. If ransomware is suspected:
- Do not pay by default. Preserve ransom notes and samples.
- Use backups to restore (after you’re sure the system is clean).
8. Update & patch your OS/apps, then re-scan.
9. If problems persist, seek professional help . In a business, isolate affected devices and inform stakeholders.
12) For Small Businesses: Policies That Move the Needle
- Security awareness training every 6–12 months; phishing simulations help.
- Acceptable Use Policy: covers software installs, data handling, removable media.
- Patch management with defined SLAs (e.g., critical within 7 days).
- Application allow-listing for critical endpoints/servers.
- Email security gateway with attachment sandboxing and impersonation detection.
- Centralised logging and alerting; know who to call when alerts fire.
- Incident Response Plan: roles, runbooks, contact tree, decision thresholds.
13) Myths vs. Reality
-
Myth: “Macs don’t get malware.
”Reality: They do-often via adware, profiles, and malicious installers. Patching and good hygiene still matter. -
Myth: “Antivirus slows my PC, so I turned it off.”
Reality: Modern solutions are lightweight; the risk of disabling protection far outweighs minor performance hits. -
Myth: “I only visit safe sites.”
Reality: Legitimate sites can be compromised; malvertising campaigns abuse ad networks to deliver payloads. -
Myth: “Two products = double protection.”
Reality: Running two real-time AV engines can conflict and reduce protection.
14) Advanced but Practical Extras (Optional)
- Application isolation: Open unknown files in Windows Sandbox or a disposable VM.
- Script control: Restrict PowerShell, Office macros, and WSH for non-admins.
- Browser containers/profiles: Separate work, banking, and general browsing.
- Hardware security keys for critical logins to crush phishing.
- Email DMARC/DKIM/SPF (business): Reduce spoofing and enforce authentication.
15) A Minimal, Modern Security Stack (Starter Recipe)
For individuals/families:
- OS auto-updates + browser auto-updates
- Reputable AV with web filtering
- Password manager + MFA
- Cloud backup (versioned) + periodic offline copy
- Hardened browser with limited extensions
For small businesses:
- Managed EDR with central console
- Email security gateway + DNS filtering
- Patch management and asset inventory
- Enforced MFA + SSO where possible
- 3-2-1 backups with immutability
- Documented incident response runbooks
Many of these are suitable for a stand-alone computer, but in a corporate sense, there are less well-known packages that are more suited to providing broader and more robust protection. It is important to note that no antivirus program can provide 100% protection against all threats, so it is important to also practice safe browsing habits and be cautious when downloading and opening files from unknown sources. It is also a good idea to keep your antivirus software up to date, as new threats and vulnerabilities are constantly being discovered.
Worried about the security of your computer network?
Contact Chris on: 0438 855 884 or sales@computingaustralia.group
FAQ
Is free antivirus enough?
For many home users, yes-if you combine it with safe habits, updates, and backups. For business or anyone handling sensitive data, step up to business-grade or managed EDR for better visibility and response.
Should I pay the ransom if hit by ransomware?
Generally no -payment doesn’t guarantee recovery and may invite repeat targeting. Focus on containment, evidence collection, and recovery from clean, offline backups. Seek expert guidance.
Do VPNs stop viruses?
No. A VPN encrypts traffic and can protect against some network threats and snooping on public Wi-Fi, but it doesn’t replace antivirus, patching, or safe behaviour.
How often should I back up?
At least weekly for home users; daily (or more) for business-critical data. The right answer is “often enough that losing anything between backups is acceptable.”
How can I protect my devices from phishing attacks?
Stay cautious of unsolicited emails, links, and attachments. Use multi-factor authentication, enable email filtering, and educate yourself and your team on spotting phishing attempts. Avoid clicking on unknown or suspicious links.
