Modern antivirus and endpoint protection tools monitor your system for suspicious files, unsafe websites, unusual behavior, and malicious activity.
When a threat is detected, your antivirus displays an alert — but not all alerts require the same response.

This guide explains the most common types of antivirus alerts, what they mean, and what steps you should take to protect your device and your business.

✅ Common Types of Antivirus Alerts

1. Virus or Malware Detected

This appears when the antivirus identifies a harmful program such as:

• Trojans

• Worms

• Keyloggers

• Spyware

• Ransomware

What to do:

1. Do not open any suspicious files.

2. Allow the antivirus to quarantine or remove the threat.

3. Restart your device if prompted.

4. Submit a support ticket if the alert keeps reappearing.

2. Suspicious Behavior Blocked

This means the antivirus noticed activity that resembles malware behavior, such as:

• Unusual file modifications

• Attempts to access protected areas

• Apps trying to install without permission

What to do:

1. Review the name of the application causing the alert.

2. If you don’t recognize it, let the antivirus block it.

3. If it is legitimate software, contact support before allowing it.

3. Unsafe Website Warning

Triggered when you attempt to visit a site known for:

• Phishing

• Fake login pages

• Malware downloads

• Unsecure connections

What to do:

• Do not continue to the website.

• Close the browser tab.

• If you clicked the link from an email, it may be phishing — report it.

4. Potentially Unwanted Application (PUA/PUP)

These may not be outright malware but can cause issues.
Examples include:

• Adware

• Browser toolbars

• Unapproved optimization tools

• Software bundled with installers

What to do:

• Allow the antivirus to remove or block the application.

• If you need the program for work, confirm with IT first.

5. Firewall Block Alert

Your firewall blocked an application or connection attempt.

What to do:

• If you initiated the action (e.g., launching a work app), click Allow only if you trust it.

• If unsure, choose Block and contact support.

6. Outdated Antivirus Definitions

This means your antivirus software isn’t fully updated and may miss new threats.

What to do:

1. Open your antivirus dashboard.

2. Run Update or enable Automatic Updates.

3. Reboot if required.

If updates fail repeatedly, contact support.

7. Full Scan or Quick Scan Recommended

Your antivirus may prompt you to run a scan if:

• The system is overdue

• Suspicious background activity is detected

• A recent threat was removed

What to do:

• Run the recommended scan.

• Avoid heavy computer use during the scan for best results.

🛠️ What to Do Immediately If You See an Alert

Regardless of the alert type, follow these best practices:

1. Do NOT ignore or bypass the alert.

Even minor alerts indicate a potential risk.

2. Read the message carefully.

Look for keywords like:

• “Quarantined”

• “Blocked”

• “Removed”

• “Suspicious activity”

• “Failed to clean”

3. Avoid opening unknown downloads or email attachments.

If the alert appears right after you clicked something, stop using the file immediately.

4. Disconnect from the internet if you suspect a serious threat.

This limits potential damage while IT investigates.

5. Submit a support ticket if you’re unsure.

Include:

• A screenshot of the alert

• What you were doing when it happened

• The name of the flagged file or app

Our team will help determine whether the alert is legitimate and what action to take.

🔍 How Antivirus Software Protects You

Most modern security tools include:

• Real-time protection

• Email scanning

• Web filtering

• Ransomware protection

• Behavior-based threat detection

• Zero-day exploit protection

• Cloud threat intelligence

This layered security helps stop threats before they cause damage.

🔄 What Happens When Antivirus Quarantines a File?

Quarantine means:

• The file has been isolated

• It cannot run or spread

• IT can review and safely delete or restore it

You should never manually open or restore quarantined files without consulting support.

🚨 If You Believe Your Device Is Infected

Take these steps immediately:

1. Disconnect from Wi-Fi or unplug network cable

2. Stop using the device

3. Do not enter passwords or open sensitive applications

4. Contact OneStop Northwest support at once

Quick response reduces risk of data loss, ransomware, or unauthorized access.

🛡️ Keeping Your Device Safe: Best Practices

• Keep antivirus and operating systems updated

• Enable automatic scans

• Use strong, unique passwords

• Avoid downloading unknown software

• Enable MFA on work accounts

• Back up important files (OneDrive, SharePoint, Zoho WorkDrive, Google Drive)

• Report suspicious emails immediately