Each time you go to the Options section of your browser to clear your browsing history after you finish a browsing session (or press Ctrl+Shift+Del for the same effect), do you move on, assured that no one can find out what you’ve been doing? Unfortunately, nothing’s this simple with computers. If you need to cover your tracks, you always need to do it in multiple ways. Here’s how people can get at your browsing history after you’ve deleted it the normal way.
Undoing a history deletion
Browsers store browsing history data in files, just the same as any other information. When you clear your browser’s history, these files are simply deleted the way any other files are. If someone wants to look at deleted browser history records, they simply need to fire up file recovery software and get it to recover these files. To recover deleted history on Chrome, for instance, they could point their recovery software at the path C:\i0 < your user account>Data (where your user account is simply whatever your user account in Windows is called).
Mining the DNS cache
Every browser uses DNS servers to know where to find every website that you ask for. Each web address that you visit is stored in the DNS cache. Clearing your browser history doesn’t do anything about this perfect set of browsing history records.
Anyone who wishes to spy on your browsing activity simply needs to open the Command Prompt and type in the string ipconfig /displaydns . Right away, they’ll get a full list of all the websites that you visited since the last time your computer was started (just the websites, not the individual pages on them).
Fortunately, a computer restart clears the DNS cache. If you want to clear it without restarting your computer, you need to type the string ipconfig /flushdns into the Command Prompt and hit Enter.
Mining the router
Most routers come with the ability to store information about all traffic incoming or outgoing. Luckily, traffic log functions are usually disabled by default. Anyone who wants to spy on you, though, simply needs to surreptitiously turn it on. They can then come back and view a detailed account of every single move that you’ve made on Internet. Clearing your browser history does nothing to the log on the router. That needs to be cleared separately.
Where spies can’t go to look at your browser history
Many guides on the Internet recommend that you look at the index.dat files on a computer if you want to spy on someone’s browsing habits. This isn’t good advice, though. While index.dat files do contain browsing records, they are cleared the moment a user clears the history on his browser. If these files contain browsing information, the spy in question might as well head directly to the browser and take a look.
Other guides tell you that you can recover deleted browsing history by firing up System Restore. This, again, is incorrect. System Restore does nothing to recover browser history.
Here’s the takeaway
It can be very hard to hide your tracks on a computer. If you really wish to keep your browsing habits a secret, the only way is to do your browsing on a secret Internet connection and device that no one else knows about. If you wish to browse the Internet on a common computer or Internet connection, you’ll never be completely safe.