Should you disconnect your computer from Internet in case of virus attack?

Should you disconnect your computer from Internet in case of virus attack?

When faced with a virus attack on your PC, the question often arises: should you disconnect from the Internet or not? It's a common recommendation to sever the Internet connection when dealing with a virus invasion. But is it really the best move, or even necessary?

Computer viruses pose a persistent threat to digital security, targeting systems with alarming frequency. These malicious programs exploit vulnerabilities in software and networks, wreaking havoc on both personal and professional devices. Understanding the prevalence of these attacks is crucial for implementing effective cybersecurity measures and safeguarding against potential breaches.

Imagine finding out that your Windows system has been infiltrated by a malicious virus. Online advice suggests an immediate Internet disconnection. Unplugging the network cable and deactivating WLAN in Windows buys you time to tackle the malware. Usually, the reason behind this advice isn't fully explained. This begs the question: Is disconnecting from the Internet truly essential? The answer isn't straightforward, as there are two compelling reasons for opting to cut off your Internet connection:

  • Firstly, some malicious code, like Remote Access Trojans (RATs), grants attackers full control over your system. By disconnecting, you block their access and gain the upper hand in removing the threat.
  • Secondly, ransomware viruses often not only encrypt your data but also upload it to the attackers' servers beforehand. Disconnecting swiftly can prevent this data from falling into the wrong hands.

On the flip side, most antivirus programs perform better with an active Internet connection. They rely on extensive databases hosted by antivirus manufacturers, containing fingerprints of dangerous files. Additionally, some antivirus programs use file reputation-based detection, which requires online access to assess a file's origins and previous detections. 

Tests conducted by AV-Comparatives reveal significant disparities in detection rates between online and offline scans. For instance, Avira detects 99.1% of malware online compared to 92.5 % offline, and Microsoft Defender detects 95.8% online versus 77% offline.

Considering these findings, it appears unwise to conduct a virus scan without an active Internet connection. Nevertheless, if you suspect malware, it's prudent to perform a swift scan, which can be concluded within minutes. In the interim, you can procure a current secondary scanner, like Kaspersky Rescue Disk or Avira Rescue System, and transfer it to a USB stick. By booting your PC with this device, you can execute a comprehensive scan, shielding yourself from potential online threats.

If you still suspect lingering malware, disconnecting from the Internet for a detailed analysis is wise. This ensures a thorough examination of your system without the concern of data leaks.