McAfee AVDCDE-AA-AA User Guide - Page 259

Using Specialized Scanning Tools Heuristic scanning technology enables the E-Mail Scan extension to recognize new viruses based on their resemblance to similar viruses that the module already knows. To do this, the extension looks for certain "virus-like" characteristics in the files you've asked it to scan. The presence of a sufficient number of these characteristics in a file leads the extension to identify the file as potentially infected with a new or previously unidentified virus. Because the extension looks simultaneously for file characteristics that rule out the possibility of virus infection, it will rarely give you a false indication of a virus infection. Therefore, unless you know that the file does not contain a virus, you should treat "potential" infections with the same caution you would confirmed infections. The E-Mail Scan extension starts out without any heuristic scan options active. To activate heuristic scanning, follow these substeps: a. Select the Enable heuristics scanning checkbox. The remaining options in the dialog box activate. b. Select the types of heuristics scanning you want the E-Mail Scan extension to use. Your choices are: - Enable macro heuristics scanning. Choose this option to have the extension identify all Microsoft Word, Microsoft Excel, and other Microsoft Office files that contain embedded macros, then compare the macro code to its virus definitions database. The extension will identify exact matches with the virus name; code signatures that resemble existing viruses cause it to tell you it has found a potential macro virus. - Enable program file heuristics scanning. Choose this option to have the E-Mail Scan extension locate new viruses in program files by examining file characteristics and comparing them against a list of known virus characteristics. The extension will identify files with a sufficient number of these characteristics as potential viruses. - Enable macro and program file heuristics scanning. Choose this option to have the extension use both types of heuristics scanning. McAfee recommends that you use this option for complete anti-virus protection. Š NOTE: The extension will use heuristic scanning techniques only on the file types you designate in the Program File Extensions dialog box. If you choose to scan All files, it will use heuristic scanning for all file types. c. Click OK to save your settings and return to the E-Mail Scan Properties dialog box. User's Guide 259