Trojan-Downloader.Win32.Agent.fcav is a malicious trojan downloader virus that overwrites critical windows files with itself or replace other trojan files on them, which are terrible to the affected system. Trojan-Downloader.Win32.Agent.fcav frequently pop-ups advertising messages to interrupt computer users and more severely they may harm the data on computer systems. Trojan-Downloader.Win32.Agent.fcav opens up firewalls and gathers personal data such as personal financial information. Trojan-Downloader.Win32.Agent.fcav takes over system resources and slows down computers. Trojan-Downloader.Win32.Agent.fcav registers a 32-bit in-process server DLL in the corrupted system and downloads files to the computer without user consent, which will lead to security risk.