TROJ_DIGMINEIN.A

This cryptomining bot was seen spreading through Facebook Messenger and was first observed in South Korea. The malware is sent to victims posing as a video file but in reality is an AutoIt script.

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

As of this writing, the said sites are inaccessible.

It connects to certain websites to send and receive information. However, as of this writing, the said sites are inaccessible.

Arrival Details

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

This malware arrives via the following means:

• Downloaded through Facebook Messenger.

Installation

This Trojan adds the following folders:

• %Application Data%\{User name}

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

It drops the following copies of itself into the affected system:

• %Application Data%\{User name}\cherry.exe

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Google Updater = %Application Data%\{User name}\cherry.exe

Other System Modifications

This Trojan adds the following registry entries:

HKEY_CURRENT_USER\Software\Codec
Installed = Yes

Download Routine

This Trojan connects to the following website(s) to download and execute a malicious file:

• http://ofulo.{BLOCKED}v.bid/api/cherry/7za.exe
• http://ofulo.{BLOCKED}v.bid/api/cherry/files.7z

It saves the files it downloads using the following names:

• %Application Data%\{User name}\files.7z ←Password protected file containing malicious files.
• %Application Data%\{User name}\7za.exe ← Legitimate 7-Zip file.

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

As of this writing, the said sites are inaccessible.

Other Details

This Trojan connects to the following website to send and receive information:

• http://ofulo.{BLOCKED}v.bid

It does the following:

• Execute the following command:
  
  • "%Program Files%\Google\Chrome\Application\chrome.exe" --enable-automation --disable-infobars --load-extension=%Application Data%\{User name}

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

However, as of this writing, the said sites are inaccessible.