Re: DDoS Attack

[Andrew Anderson <koserve99 () hotmail com>]

In-Reply-To: <3ECD0537.7050208 () valueweb com>

- The request strings look like they belong to a GT Bot.
- As for the erroneous request it looks like it's a parsing error in 
apache.
- As a suggestion I would filter out any get requests with the @ symbol 
unless you have any file/folders that contain the @ symbol.


> Our parent company is experiencing a very odd/severe DDoS attack coming 
> from all over the place.  For the most part, the attack is occuring at 
> the Apache level.  Log files show this request:
>
> [Tue May 20 09:13:33 2003] [error] [client 194.xxx.xxx.xxx] request
> failed: erroneous characters after protocol string: -nb GET
> !@#%!^@)&!^&!*&!%&!%!@#%!^@)&!^&!*&!%&!%!@#%!^@)&!^&!*&!%&!%!@#%!^@)&!!
@#%!^@)&!^&!*&!%&!%!@#%!^@)&!^&!*&!%&!%!@#%!^@)&!^&!*&!%&!%!@#%!^@)&!!@#%!
^@)&!^&!*&!%&!%!@#%!^@)&!^&!*&!%&!%!@#%!^@)&!^&!*&!%&!%!@#%!^@)&!-nb 
> GET 
> @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@-nb 
> GET 
> !@#%!^@)&!^&!*&!%&!%!@#%!^@)&!^&!*&!%&!%!@#%!^@)&!^&!*&!%&!%!@#%!^@)&!!
@#%!^@)&!^&!*&!%&!%!@#%!^@)&!^&!*&!%&!%!@#%!^@)&!^&!*&!%&!%!@#%!^@)&!!@#%!
^@)&!^&!*&!%&!%!@#%!^@)&!^&!*&!%&!%!@#%!^@)&!^&!*&!%&!%!@#%!^@)&!-nb 
> GET +ATH0+ + +ATH0+ + +ATH0+ + +ATH0+ + +ATH0+ + +ATH0+ + +ATH0+ + 
> +ATH0+ + +ATH0+ + +ATH0+ + +\x01TH0+ + +ATH0+ + +ATH0+ + +ATH0+ + +ATH0+ 
> + +ATH0+ + +ATH0+ + +ATH0+ + +ATH0+ + +ATH0+ + +ATH0+ + +ATH0+ + +ATH0+ 
> + +ATH0+
>
> Scans of some of the attacking IP's show BackOrifice installations.
>
> Has anyone had this sort of attack and what would be the best way to 
> combat it?  Not much luck from the upstream(s) thus far.

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