User-Agent begins with "User Agent::"

[Umbra]

I've been blocking any user agents that begin with "User Agent:". However, in the last month or so, there's been a lot more occurences of "User-Agent: Mozilla/4.0 (compatible; MSIE..." and they're coming from various dynamic broadband IPs and from various providers. Any ideas what these are?

[wilderness]

You mean besides a PITA ;)

Possibly the upgrade to IE 7.0 "may" be related?
(Hard for some of us to believe that folks remain devoted to such crap, however we're not the masses.)

Don

[keyplyr]

I've benn blocking this for over a year:

RewriteCond %{HTTP_USER_AGENT} ^User-Agent [OR]

99% of the time this is a SPAM agent attempting to abuse my form inputs.

[incrediBILL]

I block it 100% and the amount of occurrence on my site, which has quite a bit of traffic, makes it statistically insignificant to the point that it couldn't be a real browser used by a significant amount of people.