The volume of malware circulating online is at record levels, with new threats like ransomware emerging all the time.
Give the amount of malicious software being released on a daily basis, and the constantly evolving nature of some self-propagating threats, you’re at real risk of becoming a victim.
But what do you do if your computer is infected with a virus, or if its performance dramatically slows down (often indicating it’s become part of a botnet of infected devices)?
The first and most important step is to remain calm, and avoid doing anything hasty.
In a lot of cases, panic is the emotion the people responsible for infecting your device are hoping for.
For instance, ransomware is software designed to restrict user access to files and folders until a fee is paid – usually in an untraceable digital currency like bitcoin.
Criminals use all sorts of psychological tricks to create a sense of urgency, which reduces the amount of time their victims have to contact the police – or study articles like this.
In the moments after a device starts behaving erratically, it’s easy to over-react or make a bad decision.
With ransomware, giving into urgent demands for payment rarely achieves the intended outcome. If you’ve paid once, you’ll probably pay again.
Plus, the ransomware software is still embedded on your device, so it could be deployed again at any time.
There are millions of different malware strains online, and a plethora of domestic devices that could become infected.
It would take a book – possibly even a trilogy – to cover every permutation of infection and resolution.
However, these general tips should go a long way to tackling malware at source.
We’re focusing on desktop and laptop computers, but we’ll study tackling malware on smartphones in the near future.
We’re also assuming there’s a tangible problem – loads of pop-ups, strange desktop icons, web browsers loading random pages – rather than your system simply being a bit slow.
- Firstly, disconnect your computer from the internet. This won’t stop the infection, but it could prevent it from getting worse. It’ll also ensure nobody can rummage through your hard drive, or monitor future online activity before stealing personal data.
- Next, use a separate device to go online and research the symptoms. Anti-malware firms are proactive at publishing updates on current viruses, and it’ll be much easier to tackle the problem once the computer’s strange behaviour has been given a diagnosis.
- Start the computer in Safe mode. On a Mac, hold the Shift key as the startup tone plays, and release it when the Apple logo appears. Linux also requires the left Shift key to be held down, whereas Windows 7 and 8 users should tap F8 and select Safe Mode.
- With the computer running at a fairly basic level, delete any temporary internet files off the hard drive. Search for Disk Cleanup on Windows, or use Finder on a Mac to search for caches and temp files. Linux users may wish to use a package like BleachBit.
- If you already have anti-malware software installed, it presumably missed the infected file or webpage. Alternatively, perhaps certain functions have been disabled. Try to load the program, giving it the maximum permissions and running a deep search (or a full scan).
- If antivirus software won’t work, the malware might be targeting it; the Goner virus tries to destroy any antivirus software it finds. Download an on-demand scanner using a separate web-enabled computer, and transfer it to the infected device via a USB stick.
- If your antivirus software stops working mid-scan, the device probably has a deeply embedded virus that won’t let itself be removed. It may be necessary to wipe the hard drive and reinstall the operating system, effectively restoring the computer to its factory settings. This is when having copies of personal data is worth its weight in gold – underlining the importance of backing up files and folders regularly. Even if you haven’t been doing this, you might be able to save non-program files onto a USB stick without copying the virus.
- If the antivirus software reports a fault but can’t resolve it, you may need to install a dedicated scanner like Malwarebytes. Follow the procedure in point 6, having researched the best programs for your specific problem on a non-infected web-enabled device.
- Once any malware has been removed, delete every web browser installed on the computer. Reconnect to the internet, before downloading and reinstalling them. This removes any risk of reinfection from malware that might be buried within an old browser’s files.
- As added precautions, reboot your system a couple of times and change as many account passwords as possible. Avoid sensitive activities like online banking for a few days, until you feel more confident about using web browsers again.
Of course, prevention is always better than cure when tackling malware.
Install a reputable antivirus package and keep it running in the background, with permission to perform regular device scans and check webpages/emails/attachments.
Backup sensitive data like email archives to the cloud or an external hard drive, either automatically or manually. Make manual data backups part of your weekly or monthly routine.
Avoid websites of dubious provenance, never open unsolicited email attachments, enter website addresses carefully and close your browser if anything untoward appears on-screen.
Image: Christiaan Colen