Odd errors from "HtBrowser"

[JohnKelly]

In my server error log I get many entries per day like the following:

[Sun Jul 11 02:27:43 2004] [error] [client 222.45.91.164] script not found or unable to stat: /usr/local/etc/httpd/htdocs/formpost.pl
[Sun Jul 11 02:27:49 2004] [error] [client 219.154.27.62] script not found or unable to stat: /usr/local/etc/httpd/htdocs/formpost.pl
[Sun Jul 11 02:54:32 2004] [error] [client 219.154.27.62] script not found or unable to stat: /usr/local/etc/httpd/htdocs/formpost.pl
[Sun Jul 11 03:04:41 2004] [error] [client 221.205.160.58] script not found or unable to stat: /usr/local/etc/httpd/htdocs/formpost.pl

The related entries in my access log show entries from:

222.45.91.164 domain.com - [11/Jul/2004:02:27:43 -0400] "POST /formpost.pl? HTTP/1.1" 302 261 "-" "HtBrowser"
219.154.27.62 domain.com - [11/Jul/2004:02:27:49 -0400] "POST /formpost.pl? HTTP/1.1" 302 261 "-" "HtBrowser"
219.154.27.62 domain.com - [11/Jul/2004:02:54:32 -0400] "POST /formpost.pl? HTTP/1.1" 302 261 "-" "HtBrowser"
221.205.160.58 domain.com - [11/Jul/2004:03:04:41 -0400] "POST /formpost.pl? HTTP/1.1" 302 261 "-" "HtBrowser"

The IP addresses are different by the user agent is always "HtBrowser". Is this a spider run amuck or someone trying to scan my site for vulnerabilities?

[steelegbr]

All of the address trace back to China under a few different owners but I have never heard of HtBrowser.

Google only returns a web page for viewing "The Gene Ontology" for HtBrowser