BackDoor.Flashback is a multicomponent backdoor for Mac OS X Lion. It is distributed under the guise of an archived Adobe Flash Player installer with the name FlashPlayer-11-macos.pkg. The main component Preferences.dylib is installed into the /Library/Preferences/.
The main malicious library Preferences.dylib terminates its work if one of the following files is found in the system:
- /Library/Little Snitch/lsd
- /Applications/VirusBarrier X6.app/Contents/MacOS/VirusBarrier X6
- /Applications/iAntiVirus/iAntiVirus.app/Contents/MacOS/iAntiVirus
- /Applications/avast!.app/Contents/MacOS/avast!
- /Applications/ClamXav.app/Contents/MacOS/ClamXav
- /Applications/HTTPScoop.app/Contents/MacOS/HTTPScoop
- /Applications/Packet Peeper.app/Contents/MacOS/Packet Peeper.app
Preferences.dylib is designed to execute various commands issued by the remote command and control server or specified in the configuration file (for example, a command to embed a JavaScript code into webpages viewed by the user). However, the library also can be used to execute any standard shell command. It can receive commands from mobile.twitter.com.