Can Malware Spread Through Wi-Fi?

Justin Oyaro

By Justin Oyaro . 12 February 2024

Cybersecurity Expert

Miklos Zoltan

Fact-Checked this

Yes, malware can spread through Wi-Fi and infect interconnected devices. In addition, Wi-Fi provides a lucrative attack vector (pathway) that cybercriminals use to propagate malware.

As an attack vector, Wi-Fi networks can be easy to exploit, and an attacker can target many vulnerable victims at once.

This article will explain how attackers can spread malware through Wi-Fi. It will also cover the following:

  • Tell-tale signs of malware infection.
  • How to avoid getting malware on Wi-Fi networks.
  • How to remove malware from your devices.

Let’s get started.

How Do Threat Actors Spread Malware over Wi-Fi Networks?

To spread malware over Wi-Fi, a threat actor needs to have malware, gain access to a Wi-Fi network, and then find a host (device to infect that will be used to spread the infection).

Here are simplified steps on how threat actors spread malware through Wi-Fi:

  1. A threat actor hacks a Wi-Fi network or sets up a fake Wi-Fi hotspot and waits for unsuspicious victims to connect.
  2. The threat actor identifies a victim and uses various techniques, such as social engineering, to access the victim’s device. Others exploit the device’s security vulnerabilities.
  3. After gaining access to a device, the threat actor pushes malware to the host. The malware can then propagate or rely on the victim’s actions to spread.
  4. The malware will then infect other interconnected devices without preventive security controls, such as antimalware programs.
  5. Even after disconnecting from the hacked Wi-Fi, the infected devices (hosts) can spread malware to other devices when they connect to their Wi-Fi networks.

Malware Propagation over Wi-Fi

Various malware spreads differently on Wi-Fi. Threat actors use multiple techniques for the initial infection to push the malware to the new host.

The techniques include using email attachments, pop-ups, spoofing websites, USB sticks, and even executing the malware on the host device.

On the host device, depending on the malware, the infection will disable security protection, replicate and spread, modify sensitive information, or use the host for command and control to launch devastating attacks.

Common malware that can spread over Wi-Fi include:

Virus

This malware is usually attached to files or executable programs and apps. Viruses are dormant, and the infection starts when a user opens the file or runs the program.

Viruses can replicate themselves and infect other files and programs. In addition, viruses on Wi-Fi networks can spread through the shared folder if the contents contain the virus.

Worm

This malware rapidly replicates and is designed to spread on its own. Worms are dangerous since they can seek out vulnerabilities in a system/network, propagate other type of malware such as ransomware, and go undetected for a long time.

Trojan

This malware masquerades as a useful software yet contains a deadly malware payload. Essentially, threat actors use trojans to carry and hide other malware.

Malicious bots

These are similar to worms and are used to propagate other malware. They also use the host to command-and-control other malware functions.

Signs Your Device Has a Malware Infection

Most malware infections will affect your device in ways that may disrupt normal operations. Here are some tell-tale signs that may indicate your device has malware:

Slow overall performance.

Malware operations from viruses, worms, and malicious bots consume a lot of system resources that you can use for other purposes.

Depending on what is happening in the background, some malware, such as worms, may run processes that consume a lot of RAM and CPU and thus affect your device’s performance.

Device overheating/loud fan.

Malware that uses a lot of CPU resources will cause your system to overheat. This will prompt the fan to spin faster to cool your system.

If your system overheats when idle, the fans spin erratically, or your system wakes up abnormally, you may have malware.

Slow internet connection and increased data usage.</h3.

Besides using system resources, malware such as bots and worms also consumes your internet bandwidth, resulting in a slower internet connection.

Bots consume bandwidth by sending various command and control requests to other interconnected devices on Wi-Fi or the internet.

New apps/frequent pop-ups/unauthorized browser changes.

Malware such as trojans downloads and install a lot of software that may not benefit you. Some of this software come as bundles and may also include other malware.

You might also experience a lot of pop-ups from apps you don’t know. You may also notice new search bars and changes to your browser’s default homepage and search engine.

Additionally, many websites you visit will redirect you to other websites.

Unusual system crashes/inaccessible files.

Malware, such as viruses, may modify your files, delete them, or make them inaccessible. Other malware, such as ransomware, will encrypt your files or lock you out of your device until you have paid a ransom.

In severe cases, malware infections that affect critical system files may cause your operating system to crash.

How to Avoid Malware on Wi-Fi Networks

There are various measures and controls that you can implement to avoid getting malware infections and attacks from Wi-Fi networks.

They include the following:

Use a premium VPN or avoid public Wi-Fi.

Avoid connecting to public Wi-Fi networks. Threat actors often compromise public Wi-Fi networks or create fake Wi-Fi hotspots to spread malware.

Disable the Wi-Fi auto connect and file sharing feature on your devices, and turn off Wi-Fi when you are not using it. If you must connect to public Wi-Fi, use a premium VPN.

Using powerful encryptions, a VPN protects your online traffic and connection from prying eyes.

Check out my guide on the best VPNs if you want to select a VPN.

Avoid opening suspicious links or files.

Don’t open attachments or links in emails from unknown senders. Threat actors spread malware through these attachments. Additionally, avoid clicking on pop-ups.

Use official websites.

Verify that you are accessing the official website anytime you surf the internet on Wi-Fi. Threat actors can spoof a website to collect sensitive data, such as login information.

Spoofed websites can also be used to deliver malware through downloads.

Change the default password on your Wi-Fi router.

Most routers’ default passwords are public information. As a result, a threat actor can easily connect to your router and spread malware to interconnected devices.

Use a password manager to create a unique, hard-to-crack password. Also, remember to change other default passwords on your devices.

Use a firewall.

A firewall helps you prevent unauthorized incoming or outgoing connections. This is helpful as it prevents threat actors from connecting to your device.

Depending on your network configuration, you can use a software or hardware-based firewall.

Install a premium antivirus/antimalware software.

A premium antivirus/antimalware software detects, prevents, and removes malware before they cause any damage to your device.

Always update your antivirus/antimalware software to protect against the latest malware and zero-day- vulnerabilities.

Keep your system and apps up to date.

Updates provide patches that fix bugs, exploits, and vulnerabilities that threat actors may use to gain access to your system.

Set your system and software programs to auto-update to get the latest updates on time.

Create regular system backups.

Backups help you recover and continue your daily operations if your system fails after a severe malware infection.

Various devices allow you to create weekly or monthly backups. Others create a system restore point each time you perform major system changes.

To be safe, create your backups (system and files) and store them on a secure storage device.

How to Get Rid of Malware from Your Devices

If you suspect that your device has been infected with malware, disconnect it from your network and perform the following:

Delete temporary files and cache.
Malware usually uses temporary files and cache to propagate through the system. Temporary files and cache also hold downloaded files that may contain malware.
Deleting temporary files and cache may help you stop the malware if it is not too late.
Use the antivirus/antimalware in safe mode.
Restart your system in safe mode and run a full system scan. Use premium antivirus/antimalware software that allows you to scan your system in safe mode.
The safe mode makes it easy for the antivirus/antimalware software to find and remove malware and other threats easily.

Reset your device/reinstall the OS.

If your device is severely infected and antivirus/antimalware software cannot remove the malware, factory reset your device.

A factory reset will wipe everything, including the virus, and allow you to start afresh without malware. You can also scan your device after a factory reset.

On devices such as PCs, it is recommended to reinstall the OS (a clean install) to eliminate corrupt system files that may cause hard-to-troubleshoot problems.

Use a system restore point/restore backups.

After a factory reset/clean install, you can restore your system with a clean backup and continue your operations normally.

On PCs, you can use the system restore point. However, this method may not work correctly if the malware corrupted the system files.

For better recovery results, back up your device and data regularly. This practice will allow you to have a restore point with little loss.

Wrap Up

Malware can be disseminated via Wi-Fi networks, causing significant damage to devices that connect to them. Beyond malware, cybercriminals also exploit Wi-Fi networks to execute a range of cyber-attacks.

To defend yourself and avoid contracting malware from Wi-Fi networks, steer clear of public Wi-Fi hotspots or utilize a premium VPN when connection is necessary.

Moreover, it’s crucial to have high-quality antivirus/antimalware protection installed, and to exercise caution by not clicking on dubious links.

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