killapache - PHP
How does above mentioned code works in killapache.

killapache sends GET requests with multiple “byte ranges” that will claim large portions of the system’s memory space. A “byte range” statement allows a browser to only load certain parts of a document, for example bytes 500 to 1000. It is normally used while downloading large files. This method is used by programs such as download clients to resume downloads that have been interrupted; it is designed to reduce bandwidth requirements. However, it appears that stating multiple unsorted components in the header can cause an Apache server to malfunction.

Download
http://pastebin.com/gWB76qmj