A quick inspection learned that the culprit was n-CASE, "a small application that is downloaded to your computer and runs in the background looking to show websites with information, offers and products that match keywords you are looking for", to cite the firm behind it.

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According to some sites, n-CASE generates a log of your surfing activity, including the web pages you visit and in which order you visit them. The log is then uploaded to the n-Case server and used to open advertisements that fit your preferences.