TSPY_EMOTET.L

This spyware sniffs network packets to steal information. It arrives via spammed messages aimed at German online banking users.

To get a one-glance comprehensive view of the behavior of this Spyware, refer to the Threat Diagram shown below.

This spyware arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It executes then deletes itself afterward.

As of this writing, the said sites are inaccessible.

It deletes the initially executed copy of itself.

Arrival Details

This spyware arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

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

• %Application data%\Microsoft\{random 3 characters}{random string}.exe

It drops the following files:

• %Application data%\Microsoft\{random number}.bat - This will delete the executed copy and delete itself after

It executes then deletes itself afterward.

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

• {process id}I
• {process id}M

It stays memory-resident by creating remote threads:

• explorer.exe

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random 3 characters}{random string}.exe = "%Application data%\Microsoft\{random 3 characters}{random string}.exe"

Other System Modifications

This spyware adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Office\Common\{random 1}

HKEY_CURRENT_USER\Software\Microsoft\
Office\Common\{random 1}\
{random 1}RS

HKEY_CURRENT_USER\Software\Microsoft\
Office\Common\{random 1}\
{random 1}SS

HKEY_CURRENT_USER\Software\Microsoft\
Office\Common\{random 1}\
{random 1}PS

Download Routine

This spyware connects to the following URL(s) to download its component file(s):

• {BLOCKED}.{BLOCKED}.146.109:8080
• {BLOCKED}2.{BLOCKED}4.110.228:8080
• {BLOCKED}.9.{BLOCKED}6.20:8080
• {BLOCKED}2.{BLOCKED}3.232.235:8080
• {BLOCKED}2.{BLOCKED}3.237.6:8080
• {BLOCKED}.{BLOCKED}.0.5:8080
• {BLOCKED}.{BLOCKED}.152.124:8080
• {BLOCKED}.{BLOCKED}.69.191:8080
• {BLOCKED}.{BLOCKED}.218.166:8080
• {BLOCKED}4.{BLOCKED}.183.196:8080
• {BLOCKED}.{BLOCKED}1.25.23:8080

As of this writing, the said sites are inaccessible.

Other Details

This spyware deletes the initially executed copy of itself

NOTES:

{Random string} can be one of the following:

• windows
• video
• update
• system
• sock
• share
• setup
• serial
• mgr32
• error
• edit32
• crypt
• config
• common
• cap32
• boot
• bios
• audio
• api32

The downloaded PE file is a DLL. This DLL is also injected to all processes and is responsible for intercepting and logging outgoing network traffic.

It targets German banks and possible script injections:

• banking.gecapital.de/
• comdirect.de
• cortalconsors.de
• finanzportal.fiducia.de
• onlinebanking.psd-bank.de/
• postbank.de
• professionalpartners.cortalconsors.de
• ptlweb/WebPortal
• ssl2.haspa.de/onlinefiliale/banking/services
• ssl2.haspa.de/onlinefiliale/banking/authenticate/login