Excel vulnerability aids delivery of malware

Microsoft office files have long been used as a means of delivering malware payloads and researchers at Mimecast have discovered a rise in LimeRAT malware delivered using an Excel default password. Excel files are designed to be easily encrypted, which helps attackers evade detection by common malware detection systems when a file is emailed. When you lock an Excel file with a password, you are encrypting the entire file using the password as the encryption/decryption key. But there's a catch. To decrypt a given encrypted spreadsheet, Excel first tries to use an embedded, default password, 'VelvetSweatshop,' to decrypt and open… [Continue Reading]