Agent Tesla is a Windows infostealer family designed to collect sensitive data from infected systems. It commonly targets browser-stored passwords, email credentials, and other application data, then stages that information for exfiltration. Because it focuses on theft rather than disruption, it is often used in campaigns that aim to quickly turn one compromised endpoint into account access, mailbox abuse, or follow-on fraud.
In practice, Agent Tesla is frequently delivered through phishing emails, malicious attachments, or script-based loaders that hide the payload and avoid easy file-based detection. That makes controls such as attachment filtering, script restrictions, MFA, and endpoint telemetry especially important. Defenders also watch for unusual script execution, suspicious process chains, and outbound connections that indicate credential harvesting or data theft. The term matters because it represents a classic, adaptable infostealer threat that keeps resurfacing in different delivery chains.