Obfu is a family of PHP backdoors that operate on any PHP enabled system. The variants belonging to this family are usually heavily obfuscated to prevent an outright detection of their functionality.
Depending on the settings of your F-Secure security product, it will either automatically delete, quarantine or rename the suspect file, or ask you for a desired action.
More information on the scanning and removal options available in your F-Secure product can be found in the Help Center.
You may also refer to the Knowledge Base on the F-Secure Community site for more information.
Backdoor:PHP/Obfu allows unauthorized access to a computer system.It is a remote access tool that allows a hacker to gain access to a compromised computer, typically though a TCP or UDP port.Backdoors are usually standalone files that install themselves to the system after they are run. They then remain active in the memory listening on specific network ports for commands from a remote host.The variants in this particular family are usually sent to the compromised server through a script that exploits an RFI (Remote File Inclusion) vulnerability on the compromised machine.