Recently I noticed that my FireFox browser wasn't allowing me to search from the address bar. Instead of returning the Google results it used to, I was getting this damned web page with a Yahoo search bar at the bottom. Address of the URL was: http://urlsekk20.vmn.net. I hate anything "configuring" my very customized system for me, so I set about trying to determine what was causing it.
First I did the ol' About:Config thing in FireFox's address bar & everything looked good there.
Next I went to recently installed items, & removed a few that I suspected might cause it, rebooted, & had the same results. I also removed some toolbars that re-appeared recently from a recent install (even though I am careful to choose "No" to extraneous installs & always do a custom install). Still no go. So, no recent installs or toolbars were the culprit.
Finally I looked under Run>MSCONFIG>Startup tab, & began removing suspicious or un-needed entries. I only had 6 or so entries, so I removed all but security related items. Still no go.
Finally, I removed one "security-related" looking entry that I don't recall ever installing. It was called Visicom_antiphishing.exe. Supposedly, this somehow utilizes lists of phishing websites maintained by Panda, which I don't use. Also, I don't use anti-phishing software, just A/V & anti-malware (not at all related to Panda or Visicom). I unchecked it from start-up & rebooted. Well, wouldn't you know, the problem went away. I typed a word into the address bar & Google search results came up! Yay!
What is interesting is that research indicates this URL20.vmn.net is considered malware, but from what I could see superficially in my searches on Visicom Anti-phishing Domain Advisor, it looks like it's a legit application. I wonder if it somehow became compromised?
Needless to say, I uninstalled Visicom Anti-phishing Domain Advisor, then did a registry search for any left-over entries.
This affected both IE 8.0 & FireFox. Both were fixed by removing the Visicom anti-phishing software.