How does malware exploit zero-day vulnerabilities?

Zero-day vulnerabilities are software bugs in operating systems or applications that developers are not yet aware of and for which no official patches exist. Cybercriminals actively use such flaws to conduct covert attacks against which traditional defensive mechanisms prove powerless.

Zero-day attacks are usually very expensive and are deployed selectively against specific targets or large corporations. The malware uses the vulnerability for privilege escalation or remote code execution, allowing attackers to establish persistence in the infrastructure unnoticed by administrators.

Since it is impossible to protect against unknown vulnerabilities in advance, the security strategy is built on defense-in-depth. It includes network segmentation, monitoring for anomalous activity, using sandboxes to run suspicious files, and promptly applying security updates immediately after their official release.