Digital nightmare: malware is in your hands?
One careless click can lead to a digital disaster. Your computer slows down, strange ads start popping up, and before you know it, your colleagues report receiving suspicious emails from you. In that moment, you may be holding more than just a device – you may be holding a digital nightmare called malware. This article will help you recognize the warning signs, understand where the threat comes from, and most importantly – show you how to respond without panicking.
Is your computer freezing, ads popping up everywhere, and strange links being sent to your contacts? You might be dealing with malware. This article will help you determine whether the symptoms you're seeing are truly signs of an infection. Already suspect your device is infected? Click the box and follow the instructions.
Digital Bestiary: Meet Viruses, Worms, and Other Digital Creatures
Malware is a general term for malicious software designed to infiltrate devices, cause damage, or steal sensitive data. The most common types of malware include:
- Spyware: secretly monitors user activity and collects sensitive data (e.g., credentials, passwords, or browsing history).
- Adware: displays unwanted advertisements that can slow down your device (e.g., constant pop-up windows).
- Viruses: spread by attaching to executable files and damage data (e.g., automatically deleting important documents).
- Ransomware: encrypts data and demands payment for decryption (e.g., data theft followed by a demand to pay).
- Worms: spread without user interaction and infect other devices (e.g., via an infected email attachment).
- Trojans: disguise themselves as legitimate software but install malware (e.g., fake security tools that deliver malicious).
According to Avast, the most widespread type of malware in the Czech Republic in recent years has been trojans. They accounted for 26.8% of all threats targeting Windows and macOS devices, and 44.5% of threats on Android devices [1].
Where Can Malware Come From?
Just one wrong click and your computer can turn into a digital nightmare. An innocent-looking email, a tempting link, or downloading software from shady websites – and the problem is here. To avoid malware, you need to know where it can come from. That’s the proactive step that can protect you from getting infected [2].
Email attachments and links: Malware often spreads through phishing emails containing attachments or links to infected websites.
Illegal downloads and unverified sources: Software from suspicious websites often contains adware that gets installed along with the program.
Infected websites: Visiting a compromised site can automatically download and install malware — a method known as a drive-by download.
Mobile apps and games: Apps from unverified sources may contain malware. However, risks also exist in official app stores.
USB devices and external media: Connecting an infected USB drive can transfer malware to your device—even without an internet connection.
Pop-up windows and malicious ads: Ransomware can enter your device through pop-up windows and harmful advertisements.
Signs of an Infected Device
Recognizing that your computer or phone is infected with malware isn’t always easy. Some symptoms are obvious and clearly indicate an infection, while others can be misleading or have entirely harmless explanations. That’s why we divide the signs into two categories:
a) Clear Evidence of Infection
If you encounter any of the following issues, it's highly likely that your device is indeed infected.
- Ransom message on the screen: A message appears saying your files are encrypted and payment is required? A typical sign of ransomware.
- Changed or missing files: Files are suddenly missing, renamed, or new folders have appeared? Likely the work of a trojan.
- Pop-ups and ads: Ads or pop-up windows appear even when your browser is closed? Most likely adware.
- Changed homepage or search engine: A new toolbar or unfamiliar homepage appears in your browser? You’ve probably fallen victim to a browser hijacker.
- Antivirus not working: Your antivirus is disabled or has disappeared? A may have removed it to maintain control over your system.
- Strange messages from your account: Friends say they received a weird email from you? Someone may have stolen your login credentials and is using your account to send phishing emails.
- Login alerts from unknown devices: Got a notification about a login from another country? This could indicate data theft by an infostealer.
A curious case of malware spread occurred during an attack on the International Space Station. In 2008, malware made its way onboard via an infected USB drive brought from Earth by an astronaut. The malware, known as Gammima.AG, was designed to steal login for games.
b) Virus Hypochondria
Some common technical issues may look like signs of infection. Before you panic and start reinstalling your system, consider these possibilities:
- Low memory (RAM): Too many running programs or open browser tabs can significantly slow down your computer. Close them and monitor memory usage in Task Manager.
- Full disk: A nearly full storage drive can slow down system performance. Delete old files or use a disk cleanup tool.
- Outdated system: Old system versions or drivers can cause slowdowns and instability. Regular updates help maintain performance and security.
A slow computer isn’t always a sign of a virus. The following issues can also result from regular use:
- Slow system performance: If your system responds very slowly, it might be malware — but more often, it’s due to poor maintenance.
- Device overheating: If your device heats up even under light use, it could be cryptomining malware running in the background. However, it could just as easily be caused by poor ventilation, hot weather, or high app usage.
Conclusion
Malware can target anyone — and often does so without warning. The key is not to panic, but to act methodically. If you suspect an infection, monitor your device's behavior and follow trusted steps. Most importantly, don't forget prevention: always keep your antivirus active and up to date, download only from trusted sources, update your system and apps regularly, and be cautious with suspicious emails, links, and attachments. One careless click can trigger a digital disaster — but a well-informed user can stay one step ahead of malware.