Summary Possible intrusion.
Details
The data passed to a URL has a suspicious pathname containing ../../../..; this path might be used to access privileged files. The attacker tries to move up the directory tree to access files in other directories which would not otherwise be accessible.
Some Web applications use pathnames containing ../../../.. legitimately. You should examine the URL and the GET argument to see if they are valid, or if it is an attempt to access privileged data. If the pathname within the GET argument is an access to privileged data, and the accessed parameter indicates the access was successful, you should consider your data to have been compromised.