Canandaigua National Bank & Trust has become aware of a sophisticated phishing scheme that generates a popup message while users are logged into online banking.
The popup message appears to be from CNB (or other legitimate financial institutions) and asks users to take a survey in exchange for free gifts. Similar schemes might also ask for personal information such as login names, passwords, social security numbers, etc. The popup message includes a reference to "Canandaigua National Bank," making it seem more credible.
Please be aware that the CNB site will not generate popup windows for surveys or to ask you for personal information. If you are at all uncertain about the legitimacy of a CNB Web page or window please contact the Call Center for verification.
If such a popup appears we recommend that you ignore any actions that the popup recommends and close the window immediately. If you are logged into online banking we recommend that you log out of online banking, close all browser windows, then restart a single browser window to access online banking again.
This most recent scheme utilizes a technique called "in-session phishing ." A vulnerability exists in all major Web browsers that allows data to be exchanged between open browser windows. If a user has an active CNB online banking session open in one browser window and is viewing a Web site in a second browser window, code running on the second site can detect the CNB session taking place in the first window. The malicious code identifies the session with cnbank.com and then generates a popup window customized to read that it comes from "Canandaigua National Bank & Trust." The malicious code generated by the second Web site is not permanently installed on the user's computer, so antivirus and antimalware software are not likely to detect it.
CNB recommends that when you are logged in to any online banking system that you close all other browser windows and tabs. Once you have successfully logged out of online banking you can resume visiting other Web sites.