File Extension ENC
File extension ENC are commonly associated to files written with UUencoding. Most files using this extension have gone through encryption producing a generic ENC suffix. These files are applicable for use on several operating system platforms including Linux, Mac, and Windows. ENC extension provides preliminary security to a file because of its encryption.
UUencoding refers to the binary-to-text encoding. In simple terms, binary data is converted in to text through series of ASCII codes represented by digits 0-127. The conversion is mostly used to generate portable email attachments. It was designed primarily for UNIX systems to exchange information.
There are several programs using ENC files as part of their package. PHP and Yahoo Messenger use ENC files along with their package for complete installation. For PHP, several ISO standard files are written with *.ENC extension. These files contain information about how characters will be represented in several languages.
For Yahoo Messenger, filter1.enc is the most common file include with its package. Originally, YM's filter1.enc is named filter1.txt prior to encryption. The process of encryption changes the file extension and altering the content. Filter1.enc in YM is used to contain information in relation to the "Chat Word Filter" feature.
There are no direct known threats brought by ENC files. However, most applications including PHP and YM have reported bugs pointing to some issues with their included ENC files. In some cases, ENC files are used as containers of infectious files that can hinder a system process. Norton AntiVirus in particular appends the extension ENC on files that it detects to contain malicious instructions. So, an infected file may some what look like "W32.Nimda.enc".
Several document authoring applications are able to open and edit unencrypted ENC files. Among these applications include Microsoft Word and Notepad from Microsoft. These Windows based applications can open most files with ENC extension similar to files with File extension DOC or File extension TXT extension. On the other hand, OpenOffice.org's Writer can also open ENC files similar to what Microsoft Word can do.
Even with the capability of opening and editing files with this extension, other files are unreadable by humans due to the encryptions applied. When opened with applications for viewing, these files will prompt a file containing combinations of text, numbers, and special characters without any solid clue of its content.