How long does a computer virus takes to infect a computer?

A computer virus can be all sorts of malware, whether it’s actually a virus that self-replicates, a ransomware that freezes files, Trojans that sniff out personal information or spyware that spies on your computer usage. The length of time it will take for a virus to infect a computer depends on what it was programmed to do:

• Ransomware, for instance, will start encrypting files within seconds of downloading onto your computer. A test carried out on different types of ransomware revealed that 1,000 Word documents were encrypted from between 18 seconds to 16 minutes.
• Some viruses, however, may be timed to start infecting your machine several days after being downloaded.
• Other viruses can download in segments to try and avoid antivirus software. So for instance, only a portion of the malicious code will download, followed by another portion. When the last piece is added it begins to do its dastardly work.
• A virus can also be downloaded via an email attachment and it may start working immediately shutting down your computer.

Consistent behaviour

Some types of viruses, or malware, are consistent in their behaviour and will generally start acting as soon as they download. For instance:

• Trojan horses don’t self-replicate unlike traditional viruses but act as a sneaky means for a hacker to gain access to someones to computer steal passwords and banking information. If you don’t run antivirus software you might never know you are infected with a Trojan.
• Spyware monitors a computer user’s activity, such as the websites they visit, without the user knowing anything about it.

New viruses developing all the time

Computer viruses have been with us for decades and they are always evolving.Virus creators are clever and motivated and are always pushing the boundaries to come up with ever more ingenious methods of infecting computers.

From a hacker’s perspective, the best type of malware is that which is hard to detect, difficult to remove and can sneak past all-known defences. As such it’s difficult to predict just how the next-generation of viruses will work. This is why the behavioural detection component of BullGuard’s triple layer defences are so important; it identifies and stops next-generation viruses based on how they behave.