Ransomware
What is ransomware?
Ransomware is a type of malware that encrypts files and even entire computer systems, then demands a ransom payment in exchange for returning access. Ransomware uses encryption to block access to infected files or computer systems, making them unusable to the victims. Ransomware attacks target all kinds of files, from personal to business-critical. After a ransomware attack, the hackers or cybercriminals behind it will contact victims with their demands, promising to unlock their computer or decrypt their files after a ransom is paid. Ransomware attacks may not begin immediately. Some ransomware is designed to lie dormant on your device to keep you from identifying its source. For example, the AIDS Trojan strain did not activate until the 90th reboot of the computers it infected.
How ransomware infects your device
- Exploit kits: Malicious actors develop exploit kits to take advantage of vulnerabilities in applications, networks, or devices. This type of ransomware can infect any network-connected device running outdated software. Keep your systems and apps updated to shield your hardware and files from attacks.
- Phishing: In a phishing attack, cybercriminals will impersonate trusted contacts or organizations and send you an email with a seemingly legitimate attachment or link. This type of social engineering attack often includes a fake order form, receipt, or invoice.
- Malvertising: Attackers can distribute malware by embedding it in fake online ads in a practice known as malvertising. Even the most trustworthy sites can be compromised with malvertising. While some malvertising ads only install ransomware onto your device after you click, others will download the ransomware as soon as they load on the webpage — without requiring a click. An ad blocker, such as the one in Avast Secure Browser, can protect you against these malicious ads.
- Drive-by downloads: Attackers can prime websites with malware so that when you visit, the site automatically and secretly downloads the malware onto your device. If you’re using outdated browsers and apps, you’re especially vulnerable to this technique, but a free antivirus app can help.