Exploit:PHP/Preamble is a detection for a family of various PHP scripts.
The scripts are used to test whether a particular site is vulnerable for a Remote File Inclusion (RFI) exploitation.
Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.
An exploit is a short code that uses a vulnerability in an operating system or other software to run unauthorized code on target computers.
The scripts belonging to this family are usually used to test whether a site or a webpage is vulnerable to a Remote File Inclusion (RFI) vulnerability.
The scripts test various methods an attacker can use to introduce a malicious backdoor script onto the affected server.