All browsers have the basic function to improve user experience ie., faster web page downloading speed. Everybody wants light speed download rate, but there is a drawback to this function. Phishers can get your personal information using this function!
So, how does phishers get them? Three ways for them to get hold of your PIN and which banking sites you use.
1) Browser History Sniffing. Phishers check for link color change in your browsing history file and compare with their master list. A mismatch of colors let them know that the site have been visited by you. If you don’t want to clear cookies and set brower history to zero, then you will need to change how IE and Firefox handle visited link color.
2) Cache Timer Attacks. Cache helps to speed up performance but this loading time can give information to trackers as whether you load it from your computer or from the original site. If the loading time indicates that you are loading from your cache, then they know you have visited the site before.
3) Through Adobe Flash Cookies. Adobe Flash Cookies partner with sites such as Microsoft, eWeek, PayPal, Flickr and many other sites. So, even if you clear all cookies everyday, having Adobe Flash installed is just wasting your effort to clear cookies. What you can do is to change the Website Privacy Setting in Adobe Flash Player setting manager.
Preventing phishers from sniffing into your computer can helps reducing your risk to scams.
For more details, read Mary Landesman’s article