Administrators put up all sorts of firewalls, IDSes, Anti-virus software and other security mechanisms to control how information flows in and out but these particular "annoyances" still manage to slip through. Part of this may be the attitude that they aren't really viruses or threats. However, I would disagree as it tends to ensure that information – about the user, where the user has been and the system the user is on – is getting out without proper checking.
These methods, sometimes referred to as browser hijacking, spyware, adware, etc., are all methods of gaining access into a system without the knowledge of the user (even if the EULA or AUP of that software states that they agree to it by looking at an ad) and then forwarding that info to another party. If companies allow employees access to the Web then there is a risk of spyware or other malicious code coming in.
One of the best and strongest defenses against this is user awareness and education. Nothing beats having a user who pays attention to the activities on their machine and informs administrators and technical support of any issues, even on occasion minor ones. Inform users on what spyware is, what the risks are to the company and how to recognize it. Sometimes unusual slow downs, extra unknown activity and/or sporadic computer behavior can all signal the presence of "unknown" software.
We also want to make this protection transparent to the user so a firewall add-on like WebSense is recommended. This tool works with both software and hardware firewalls. In essence, it acts as a filter for specific malicious web activities. The flexibility and scalability of the product ensures that no matter what your users do, you can protect them (and the company) from potential external attacks. Visit Websense's website for more details and comparisons with other similar products (http://www.websense.com).
Other methods of defense include limiting which Web browser is used by your users. While most desktops run Windows, it isn't necessary to run Internet Explorer. Using alternatives to IE can help mitigate some of the activities of spyware/adware/browser hijacking. This can be avoided by using browsers that have built-in pop-up control. Netscape, Mozilla and Opera all have this feature. You can also get pop-up blockers (software specifically designed for dealing with this).
Page 2: Detecting and Removing Spyware
What I have found with these three tools is that they often find items that many of the spyware products leave behind. They have a nice "Info" feature that allows an admin/tech support person to check the status of the Registry or system status. As an example, below I've done a CWShredder check first on my system:
CWShredder v1.47.3 scan only report Windows XP (5.01.2600 SP1) Windows dir: C:\WINDOWS Windows system dir: C:\WINDOWS\system32 AppData folder: C:\Documents and Settings\fac3\Application Data Username: lyne.bourque Found Hosts file: C:\WINDOWS\system32\drivers\etc\hosts (734 bytes, A) Shell Registry value: HKLM\..\WinLogon [Shell] Explorer.exe UserInit Registry value: HKLM\..\WinLogon [UserInit] C:\WINDOWS\system32\userinit.exe, CWS.Vrape/CWS.Addclass Registry value: DefaultPrefix  http:// CWS.Vrape/CWS.Addclass Registry value: WWW Prefix [www] http:// Registry value: Mosaic Prefix [mosaic] http:// Registry value: Home Prefix [home] http:// Found Win.ini file: C:\WINDOWS\win.ini (1053 bytes, A) Found System.ini file: C:\WINDOWS\system.ini (231 bytes, A) - END OF REPORT -
Looks like my system is ok. Let's check HiJackThis!
Overall nothing serious, but if I'm feeling suspicious I can check items by selecting them and getting information as to the risk they may carry. Configuration options allow me to ignore specific enterprise implemented tasks, creating a startup log (so I can check for any potential "nasties" there) and creating backups.
The last tool, StartupList, is a simple little program that generates a notepad listing of what things begin on a Windows machine. Very handy for troubleshooting.
Now while these tools are often targeted to the home user, administrators in enterprise environments shouldn't shy away from them. Remember that attackers often don't make distinctions between home and enterprise users. All they see is a victim. These three tools can be found at Merijn.org. An interesting side note, the site has been victim of a massive DDoS, perhaps a testament to the effectiveness of the tools finding the results of bad activity?
We have to realize that protecting privacy extends beyond individual end users. Our employees might inadvertently be putting the company at risk by simply performing research for a project or receiving what seems like work-related emails. While education is an excellent method of dealing with these threats, using technology as a backup helps to keep all the bases covered.