Drupal creating folders based on search queries

Hi,

My drupal root folder had several unidentified folders which I never created, I thought this to be a security breach but after investigation my webhost provided me following reply :

I took a look at the system log and found that these folder names were all associated with a similar type of HTML query:

/var/log/messages.4:May 4 22:03:17 host2 drupal: http://www.example.net|1273028597|search|123.27.111.38|http://www.example.net/search/node/http%3A/%252Fphimexpress.net/view_epi...|http://www.example.net/|0|results|http://phimexpress.net/view_epi,12902,1,bo_suu_tap_fashion_shows_not_for... (Content).

/var/log/messages.3:May 10 16:25:20 host2 drupal: http://www.example.net|1273526720|search|190.6.195.117|http://www.example.net/search/node/http%3A/%252Ffreemovies4u4ever.blogsp...|http://www.example.net/|0|results|http://freemovies4u4ever.blogspot.com/2007/12/mean-girls-2006-dvd-rip-fr... (Content).

It looks like Drupal was attempting to make these folders in its cache based on search queries. Normally these folders and files are all stored in "/home/account/public_html/cache/normal/www.example.net/search/node". However, when the search includes that "http://" it appears that Drupal is using the second "/" as a directory, and puts the temp file in the parent folder (public_html). It would appear this is an error with the way Drupal is coded rather than a malicous attack or security flaw. The first part of those URLs get stored as "http:/" in "/home/account/public_html/cache/normal/www.example.net/search/node".