When infected with a virus, should I disconnect my computer from the internet?

It’s generally advised to disconnect from the internet during a virus attack. But is it really wise to disconnect your computer from the internet? Is it even necessary?
WLANRouter

You realize that your computer has been infected with a virus. There’s a widely circulated advice that in such a situation, you should immediately disconnect from the internet. The wisdom goes that you should unplug the Ethernet cable and disable Wi-Fi in Windows to have time to remove the malware.

Usually, the reasons for adopting this strategy aren’t explicitly stated. This raises the question: Does disconnecting your computer from the internet really make sense, or is it even necessary? The answer isn’t straightforward because there are two good reasons for disconnecting from the internet.

Firstly, one can imagine malware that allows attackers complete access to the system. For example, the so-called Remote Access Trojans (RATs) operate in this way. Such malware grants attackers full control over the infected system.

Further reading: Best Antivirus Software for Windows PCs

However, attackers can also use other types of malware to access users’ personal data. Here, you can unplug the plug at any time to remove the malware.

The second reason is that ransomware viruses often not only encrypt your data but also upload it to the attacker’s server beforehand. If you don’t pay the ransom, criminals may threaten to disclose this data. In this case, quickly disconnecting from the internet also makes sense.

pcw04_Avira-Rescue

Even if Windows cannot boot or should not be booted anymore, the bootable Avira Rescue System can still detect malware on the PC.


On the other hand, most antivirus programs have better virus detection rates when you are connected to the internet. This is because antivirus manufacturers maintain large databases on their servers containing fingerprints of dangerous files.

File-reputation-based virus detection also requires some antivirus manufacturers to have internet access. The reputation of a file includes its source and how frequently it has been identified on other computers. This data is typically most up-to-date on the manufacturer’s servers.

AV comparison tests reveal the extent of the difference in detection between offline and online scans. For example, Avira antivirus can detect 99.1% of malware with internet access and 92.5% without it. The difference is even more pronounced with Microsoft Defender: in this test, 95.8% are detected online compared to only 77.0% offline. With McAfee, the online rate reaches 99.2%, while offline it’s 65.2%.

From these figures, it appears unwise to initiate virus scans without internet access. However, because a full scan of all hard drives may take several hours, we recommend running a quick scan when there’s suspicion of malware. This can be completed in just a few minutes.

Meanwhile, you can download the latest second scanner for USB sticks and copy it onto a USB stick. For instance, we recommend the Avira Rescue System. Restart your computer with the completed stick and perform a full scan.

pcw04_Malware-Protection-Test-September-2023-AV-Comparatives

If you have access to the internet during the scan, many antivirus programs can better detect malware on your PC.


If you still suspect the presence of malware on your system, it’s advisable to disconnect from the internet for a detailed analysis. This allows you to thoroughly inspect the system without worrying about any potential data leaks during this time.

Leave a Reply

Your email address will not be published. Required fields are marked *