Due to problems with certain websites displayed incorrectly, we decided to leave ‘higher compatibility’ mode set for all applications by default. This will definitely eliminate potential problems displaying websites. However, given the principle IMON works in this mode, viruses may slip through IMON if a particular application supports download resume. At any rate, even in that case AMON would detect the infected file and block further malicious actions. If you have come across the aforementioned issue, please set your browser to Higher compatibility mode manually, or uninstall NOD32 and install version 2.12.2 available on our website for download. We would appreciate if you could set your browser to 'higher efficiency' mode and, if you encounter a problem opening certain websites, email email@example.com and provide us with the exact URL address so that we can figure out why the issue occurs. For more information on differences between active and passive mode and potential risks that stem from both modes, please read the description below: Passive (compatible) mode: Description IMON running in passive mode stores a copy of each downloaded file while each received packet sends out directly to the application (browser). When the end of the file is detected, the whole file is checked for viruses and the local copy is subsequently deleted. Side effects Given the principle of work in this mode, IMON can only partially intercept incoming file by terminating the connection before sending out the last fragment of the file. In case the browser allows fragmented file downloading, it can request the missing fragment from the HTTP server resulting in that IMON will become ineffective. Therefore, IMON has mostly a notification function in passive mode. Usage This mode is suitable for applications with a little probability of downloading a malicious code, applications which utilize the HTTP protocol only as a facilitating mean and are not primarily intended for downloading files (e.g. on-line multimedia players). Other application categories requiring passive mode are various download managers/accelerators which utilize the HTTP protocol in a specific way not usually compatible with active mode of the HTTP scanner. Active mode Description In active mode IMON stores each downloaded file. The main difference is that no file fragment is sent to the application during the download process. The whole file is sent to the application after it’s been checked for viruses. In case the file contained a malicious code, an html page informing the user about the infiltration is sent in place of it. Side effects Using the HTTP scanner in active mode may have several side effects resulting from the way of checking. Given that the whole file is received by IMON first and then, after it’s been checked, sent to the application, the application will not provide accurate information on the download progress. That’s because no data is coming from the application’s point of view (the phase when the file is being downloaded by IMON) and the whole file will be delivered at once. The difference is noticeable especially when downloading larger files. So that the user can see the current download progress, a small IMON’s window will show up after 5 sec. in the lower-right corner of the screen. Right-click the window to invoke a context menu to display detailed information on download progress, terminate download or switch to passive mode. For proper functioning of some types of applications active mode is not suitable (e.g. multimedia players which need to know the beginning of a file before the whole file is actually downloaded or applications which utilize the HTTP protocol in a specific way such as download managers). For such applications, it is necessary to set passive mode. Usage Active mode is intended for applications of which primary role is downloading files and html web pages from the Internet (e.g. web browsers). IMON running in active mode can, in most cases, prevent malicious code from entering the computer. Under certain circumstances, a malicious code can slip through IMON even if working in active mode (e.g. if the download process is interrupted and the browser sends out a request to download the missing file fragment, IMON will not get the file in its entirety and is unable to check it).