OSX_TSUNAMI.A

 Analysis by: Kathleen Notario

 ALIASES:

Backdoor:MacOS_X/Tsunami.A (Microsoft); Backdoor.OSX.Sunam.b (Kaspersky); OSX/Tsunami-A (Sophos)

 PLATFORM:

Mac OS X

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This backdoor connects to specific IRC server and joins a particular IRC channel.

It is capable of receiving and executing specific commands from the IRC server.

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

File Size:

42,348 bytes

File Type:

Mach-O

Memory Resident:

Yes

Initial Samples Received Date:

27 Oct 2011

Payload:

Compromises system security

Arrival Details

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Backdoor Routine

This backdoor connects to any of the following IRC server(s):

  • {BLOCKED}u.anonops.li

It joins any of the following IRC channel(s):

  • #tarapia

NOTES:

This backdoor is capable of receiving and executing the following commands from an IRC server:

  • DISABLE - this disables all packeting from the client
  • ENABLE - this enables all packeting from the client
  • GET {HTTP address} {save as} - this downloads and saves a file
  • GETSPOOFS - this gets the current spoofing
  • HELP - this displays the help menu
  • IRC {command} - this sends commands to the IRC server
  • KILL - this kills the client
  • KILLALL - this kills all current packeting
  • NICK {nick} - this changes the nick of the client
  • PAN {target} {port} {secs} - this performs an advanced SYN flood to a specific target at n seconds interval
  • SERVER {server} - this changes the server
  • SH {command} - this executes commands
  • SPOOFS {subnet} - this changes spoofing to a subnet
  • TSUNAMI {target} {secs} - this triggers the bot to perform a denial of service (DoS) attack on a specific target by sending packets at n seconds interval
  • UDP {target} {port} {secs} - this performs a UDP flood to a specific target at n seconds interval
  • UNKNOWN {target} {secs} - this performs a non-spoof UDP flood to a specific target at n seconds interval
  • VERSION - this retrieves the version of the client

  SOLUTION

Minimum Scan Engine:

9.200

FIRST VSAPI PATTERN FILE:

8.526.03

FIRST VSAPI PATTERN DATE:

27 Oct 2011

Scan your computer with your Trend Micro product to delete files detected as OSX_TSUNAMI.A. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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