Malware

Malware is any program written to harm you, or to work for someone else while it sits on your computer. It comes in several shapes, so a virus copies itself into other files and spreads, while spyware sits still and sends back whatever you type, passwords included. A trojan fools people instead, arriving as a free invoice tool or a photo editor while it does its real work in the background.

Almost all of it arrives in four ordinary ways, and none of them looks like an attack at the time. The first is an email attachment dressed as an invoice, a delivery note or a CV, so it gets opened without thinking. The second is a fake update, where a page claims your browser or video player is old and the download is the malware itself. The third is a USB stick, handed over by a customer or found in a car park and plugged in from curiosity. The fourth is cracked software, a paid program taken free from a forum with a small extra program inside.

None of those four needs anyone to break into anything, because all they need is one person, once, in a hurry. So the real defence is less about clever software than about an ordinary working day.

Antivirus helps and you should have it, but it mainly recognises files it has seen before, and attackers change theirs daily. So it is one lock on one door rather than a plan, and the dull rest of that plan does more. It starts with staff who can spot a bad attachment and with updates installed the week they come out. The account people use all day should not install programs, so a stray file has nowhere to settle. Then comes a backup kept where an infected machine cannot reach it, which turns a ruined week into a slow afternoon.

The surprise is the bill for the time, not for the cleaning. A shop with an infected till loses the afternoon, and an office loses the one file everybody works in. When Linkysoft is called in after an infection, most of the work is finding what the program touched and which passwords must change. That part is slow, which is why a short cybersecurity review beforehand costs a small fraction of it. It helps too that the business systems Linkysoft builds record who signed in and what they changed, because that record makes the clean-up quick instead of guesswork.