Weird HTTP Requests.

Hello ,
I have noticed the following in my URLScan error log file , i have arounf 50 MB log file with those entries only
what could it be ? is it a virus that does that ?

[08-13-2003 - 04:16:46] Client at ###.###.###.###: Sent verb 'GES', which is
not specifically allowed. Request will be rejected.
[08-13-2003 - 04:17:42] Client at ###.###.###.###: Sent verb 'GES', which is
not specifically allowed. Request will be rejected.
[08-13-2003 - 04:18:37] Client at ###.###.###.###: Sent verb 'GT', which is
not specifically allowed. Request will be rejected.
[08-13-2003 - 04:18:55] Client at ###.###.###.###: Sent verb 'GDT', which is
not specifically allowed. Request will be rejected.
[08-13-2003 - 04:20:57] Client at ###.###.###.###: Sent verb 'ET', which is
not specifically allowed. Request will be rejected.
[08-13-2003 - 04:21:32] Client at ###.###.###.###: Sent verb 'GES', which is
not specifically allowed. Request will be rejected.
[08-13-2003 - 04:22:41] Client at ###.###.###.###: Sent verb 'GDT', which is
not specifically allowed. Request will be rejected.
[08-13-2003 - 04:22:52] Client at ###.###.###.###: Sent verb 'GFT', which is
not specifically allowed. Request will be rejected.
[08-13-2003 - 04:23:07] Client at ###.###.###.###: Sent verb 'GDT', which is
not specifically allowed. Request will be rejected.
[08-13-2003 - 04:23:09] Client at ###.###.###.###: Sent verb 'GE', which is
not specifically allowed. Request will be rejected.
[08-13-2003 - 04:23:17] Client at ###.###.###.###: Sent verb 'ET', which is
not specifically allowed. Request will be rejected.
[08-13-2003 - 04:23:59] Client at ###.###.###.###: Sent verb 'GE×', which is
not specifically allowed. Request will be rejected.
[08-13-2003 - 04:24:23] Client at ###.###.###.###: Sent verb 'GE', which is
not specifically allowed. Request will be rejected.
[08-13-2003 - 04:24:48] Client at ###.###.###.###: Sent verb 'GE', which is
not specifically allowed. Request will be rejected.
[08-13-2003 - 04:26:03] Client at ###.###.###.###: Sent verb 'GײT', which is
not specifically allowed. Request will be rejected.

Thanks ,