Backdoor:OSX/Tsunami.A

Summary

Backdoor:OSX/Tsunami.A is a distributed denial-of-service (DDoS) flooder that is also capable of downloading files and executing shell commands in an infected system.

Disinfection & Removal

Automatic Disinfection

Allow F-Secure Anti-Virus for Mac to remove the relevant files.

Technical Details

Backdoor:OSX/Tsunami.A is an OS X platform ported version of the IRC bot for Linux called "Kaiten wa goraku." Upon execution, it connects to an IRC server and then joins a password protected channel where it waits for further commands.

It is mainly a distributed denial-of-service (DDos) flooder, hence the name Tsunami. However, it is also capable of performing other actions such as downloading additional files and executing shell commands in an infected system. These actions could grant the bot master almost a full control of the infected system.

The IRC parameters, drop files and launch points differ between variants. As of this writing, two variants have been found. The table below describes the characteristics of the two variants.

IRC Server:Port	Channel	Drop Files and Launch Points
pingu.anonops.li:6667	#tarapia	None. It must be installed manually by the user or an attacker who has access to the system
x.lisp.su:6667	#harbour	-
/System/Library/LaunchDaemons/com.apple.logind.plist	-	launch point
/usr/sbin/logind	-	copy of the malware

As of this writing, both servers are not accessible