While surfing Web sites of questionable repute, I've come across many programs that act maliciously. Often, they are the sort known as spyware or adware, which are insidious programs designed to install themselves in hard, if not impossible to find places on your computer and then either collect information about you and report it back to someone, or simply display unwanted advertisements. These can be particularly annoying, because the advertisements are often unsavory or downright offensive. But if these are annoying, just think what such programs might do. The thought should stir you to try to do something about these things.
While there are a number of antiadware and antispyware programs that you can install, which will keep an eye on your computer and inform you when a known-bad program attempts to install itself, I've found that in this escalating battle, the unwanted programs are often able to sneak through, undetected by your guardian software.
Curiously though, I've been able to discover many of these using a very simple tool: Windows System Information. You can open the System Information utility from the Accessories, System Tools menu. Once there, navigate through the tree to "Internet Explorer" which is invariably the program exploited by these ne'er-do-wells, then to "Cache" and then select "List of Objects".
Once selected, the pane on the right may show some surprising results. The codebase column, which shows the URL that these programs came from, is particularly interesting. Often the URL will be one that you can trust. If it isn't, then you know at least that you have a misbehaving program installed, and you can deal with it at that point.
As an administrator, you may want to regularly check this list for changes. You can automate this with a little scripting, by saving it as text and running WinDiff or a comparable program.
Thomas Alexander Lancaster IV is a consultant and author with over ten years experience in the networking industry, focused on Internet infrastructure.