BKDR_EMDIVI.TRYL

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.

It does not have any propagation routine.

It executes commands from a remote malicious user, effectively compromising the affected system.

It retrieves specific information from the affected system.

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.

Installation

This backdoor adds the following mutexes to ensure that only one of its copies runs at any one time:

• 51d2127a118abf444eff7f54285e8f8e

Propagation

This backdoor does not have any propagation routine.

Backdoor Routine

This backdoor executes the following commands from a remote malicious user:

• Enumerate files and folders
• Delete files and folders
• Download files
• Upload files
• Execute files
• Get file attributes
• Enumerate processes
• Perform remote shell
• Loads a library using LoadLibrary API
• Import functions from a library using GetProcAddress API
• Choose HTTP Authentication
• Setup Proxy auto-configuration
• Gather Firefox settings from prefs.js
• Gather proxy settings from proxy.pac
• Gather proxy settings from windows registry
• Clear Security Event Logs
• Sleep

It connects to the following URL(s) to send and receive commands from a remote malicious user:

• http://www.{BLOCKED}l.epac.to/index.php
• http://{BLOCKED}o.softether.net/index{2 random numbers}.html
• http://{BLOCKED}p.ninjia.org/index{2 random numbers}.html
• http://{BLOCKED}8.wariskind.com

Information Theft

This backdoor retrieves the following information from the affected system:

• Host name
• Process ID of the malware
• Memory Size (RAM)
• Internet Explorer Version
• Windows OS Version
• System Language
• Location
• Time Zone Information

Other Details

This backdoor connects to the following URL(s) to check for an Internet connection:

• http://www.msftncsi.com/ncsi.txt
• http://www.microsoft.com/en-us/default.aspx
• http://www.yahoo.co.jp

NOTES:

It enumerates all visible windows and compares each window's title bar text with the following strings:

• OllyDbg
• W32Dasm
• Wireshark
• Fiddler
• SoftICE
• Process Explorer
• Process Monitor
• Process Hacker

If a window's title bar text contains any of the said strings, it pauses the execution of its malicious routine by performing a Sleep command.