PHP/Pirus is the first virus written with PHP. PHP is a server side scripting language for web servers.
Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.
When PHP/Pirus.A is executed, it will search for files with ".php" and ".htm" from the current directory. If such files are found, it will append a small code that will execute the virus from a separate file. The name of the file is "pirus.php".
Technical Details: Katrin Tocheva and Sami Rautiainen, F-Secure; January 2001