is this an attack attempt?

Sun Jun 9 20:09:32 EDT 2002

Hi all,

I've noticed a small number of entries like the one below in my /var/log/apache/access_log file. In the below sample, "x.x.x.x" represents the ip address.

x.x.x.x - - [09/Jun/2002:18:54:52 -0500] "GET /default.ida?NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN%u9090%u6858%ucbd3%u7801%u9090%u6858%ucbd3%u7801%u9090%u6858%ucbd3%u7801%u9090%u9090%u8190%u00c3%u0003%u8b00%u531b%u53ff%u0078%u0000%u00=a  HTTP/1.0" 400 334

Is someone or actually a group of people trying to compromise my web server? Is it possible to tell from the above log entry  how they are trying to compromise apache? Thanks.
Greg