A malicious domain is a web address controlled by attackers and used to support a scam, malware campaign, or credential theft operation. It may host a fake login page, a lure that looks like a legitimate service, or a download that delivers malicious code after the victim clicks through.
In cyber security, malicious domains matter because they turn a normal-looking link into an attack delivery point. They are often used in phishing and spearphishing to bypass email filters, collect passwords and session cookies, or guide users into installing infostealers and other payloads. Defenders look for suspicious registration patterns, newly created lookalike domains, unusual redirects, and links tied to known campaign infrastructure. Blocking, takedown requests, DNS filtering, and user verification through a separate channel can reduce the risk.