Help – I think I’ve lost data due to a virus – what do I do?

By on Nov 2, 2013 in Blog

First of all – don’t panic! In many cases viruses may simply prevent you from accessing anything on your computer, but the data itself may still be intact.

There are two basic steps to take if you believe a virus is present on your computer:

  1. Isolate the computer you suspect is infected
  2. Check, diagnose, and clean the infected computer (if applicable)
  3. Bonus Step: If in doubt over the above two steps – ask for help!

Now we’ll go over these two steps in more detail.


Step 1 – Isolate your computer

Your basic virus (similar to the medical variety) is usually designed with one purpose in mind – multiply and spread across all available networks and infect as many computers as possible. Of course viruses are also programmed to perform some specific malicious task – such as spreading spam, stealing data, or disabling some key function. However, let’s focus on containing the infection first.

What you want to do as quickly as possible is disconnect your computer from all networks immediately. This includes your internet connection, and any connections to your company network.

The best way to do this is to physically unplug the network cables attached to your computer. NOTE: A network cable will look similar to, or exactly like this. If you are using a wireless modem or router – then you need to turn off the power to said modem or router – NOT the computer.

One might argue that it is faster / better to disconnect the power cable and shut down the computer completely. This might seem logical to some, but the reality is that you cannot diagnose a problem or fix it if the computer is shut off. Isolating the computer from any networks contains the threat (if it exists), and this is enough to ensure the security integrity of the rest of the network.

If you are on a corporate / office network and have an IT department, Helpdesk, or System Administrator – you should notify the appropriate party immediately if you suspect a virus (3rd party support services are also available if you need it). This will allow qualified parties to react quickly in case the threat is real, and they should be very helpful in getting you back in operation.


Step 2 – Check, Diagnose, and Clean

Once you’ve made sure that no other computers are at risk of becoming infected, you can now try to identify any infections on the computer.

If you have antivirus software installed on your computer (and you should) – start by updating your virus definitions. If you are unsure how to do this, just find out who makes your antivirus (e.g. Norton, Kaspersky, F-Secure etc.) and run a Google search for “update [brand] virus definitions”. This is the fastest and most accurate way to do this since every company is different, and sometimes the procedures change.

If you do not have an antivirus program installed, you can try using an online virus scan (normally free):

Note: most well-known security companies (and even Microsoft) offer free security software that you can download and install yourself.

If you are unable to connect to the Internet to download anything – there are pretty much two options left:

  1. Download the latest virus definitions using a non-infected computer using some portable storage media (like a USB key) and then manually update the virus definition file on the infected computer.
  2. Use the antivirus software available on a non-infected computer to create a bootable USB key – restart your computer – then run the security scan as part of the start-up process.

Once your antivirus software is updated – you can begin a full system scan of all drives and all file types!

If an infection is found, the software will tell you what steps to take to next. In most cases the infection can be removed without causing any data loss to occur.

If no infection was found, or if the data you were looking for is still not accessible after the virus scan has completed cleaning the infection, you should contact a professional data recovery service or your IT Helpdesk.

If no virus is found, but you are absolutely convinced something is wrong with your computer – you should always ask the professionals to assist you. The peace of mind is worth much more than the little cost.

Thanks for reading – stay safe, and stay tuned!

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