The function of an antivirus solution is to detect malicious files using malware signatures and related detection methods. Signature-based detection compares files or code patterns against known malware indicators. Antivirus may also include heuristic, reputation-based, or behavioral detection, but known malware signature scanning is the classic function. Regulating traffic based on security rules is a firewall function. Protecting against DNS poisoning is handled through DNS security, secure resolver behavior, validation mechanisms, and network protections. Protecting user credentials is primarily an identity security function involving MFA, password management, phishing resistance, and access controls. Antivirus is a core endpoint security component because malicious files commonly reach users through downloads, attachments, removable media, compromised websites, or unauthorized software. It helps prevent execution, quarantine malicious content, and alert administrators. While modern endpoint platforms go beyond antivirus, the foundational antivirus role remains malware file detection and prevention on the device. Reference/topics: Endpoint Security 4.3, antivirus; Cybersecurity 1.5, threat prevention practices.