Agent.FUP is a Trojan, which although seemingly inoffensive, can actually carry out attacks and intrusions.
It uses stealth techniques to avoid being detected by the user:
- It uses techniques included in its code to hide itself while it is active.
- It terminates processes corresponding to several security tools, such as antivirus programs and firewalls, to prevent detection.
It uses several methods in order to avoid detection by antivirus companies:
- It prevents scanning tools from running, such as Windows Registry Editor, FileMonitor, etc.
- It terminates its own execution if it detects that a memory dump program is running, such as Procdump.
- It terminates its own execution if it detects that a debugging program is active.
Agent.FUP does not spread automatically using its own means. It needs an attacking user's intervention in order to reach the affected computer. The means of transmission used include, among others, floppy disks, CD-ROMs, email messages with attached files, Internet downloads, FTP, IRC channels, peer-to-peer (P2P) file sharing networks, etc.