TSPY_EMOTET.AUSJKW

This information stealing malware arrives as spam spoofing an invoice or payment notification. If the user clicks the URL in the email, it executes a PowerShell command that downloads EMOTET. It then gathers information on the affected system and sends the information to a C&C server to determine the payload to be sent to the affected system. One of the possible payloads includes DRIDEX, a popular banking trojan.

This Trojan Spy 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 the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system. As of this writing, the said sites are inaccessible.

It deletes the initially executed copy of itself.

Arrival Details

This Trojan Spy 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 Trojan Spy drops and executes the following files:

• %AppDataLocal%\Microsoft\Windows\{string 1}{string 2}.exe - drops the file here if it has no admin privileges, also detected as TSPY_EMOTET.AUSJKW
• %System%\{string 1}{string 2}.exe - drops the file here if it has admin privileges, also detected as TSPY_EMOTET.AUSJKW
  
  where {string 1} and {string 2} is a combination of any of the following strings:
  • agent
  • app
  • audio
  • bio
  • bits
  • cache
  • card
  • cart
  • cert
  • com
  • crypt
  • dcom
  • defrag
  • device
  • dhcp
  • dns
  • event
  • evt
  • flt
  • gdi
  • group
  • help
  • home
  • host
  • info
  • iso
  • launch
  • log
  • logon
  • lookup
  • man
  • math
  • mgmt
  • msi
  • ncb
  • net
  • nv
  • nvidia
  • proc
  • prop
  • prov
  • provider
  • reg
  • rpc
  • screen
  • search
  • sec
  • server
  • service
  • shed
  • shedule
  • spec
  • srv
  • storage
  • svc
  • sys
  • system
  • task
  • time
  • video
  • view
  • win
  • window
  • wlan
  • wmi

(Note: %AppDataLocal% is the Application Data folder found in Local Settings, where it is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local 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.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

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

• M{hash of full file path}
• Global\M{volume serial number}

Autostart Technique

This Trojan Spy registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\{string 1}{string 2}
ImagePath = %System%\{string 1}{string 2}.exe
where {string 1} and {string 2} is the same name as the drop file

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{string 1}{string 2} = "%AppDataLocal%\Microsoft\Windows\{string 1}{string 2}.exe

Download Routine

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

• http://{BLOCKED}.{BLOCKED}.159.58:443/
• http://{BLOCKED}.{BLOCKED}.252.178:8080/
• http://{BLOCKED}.{BLOCKED}.245.37:7080
• http://{BLOCKED}.{BLOCKED}.1.167:8080
• http://{BLOCKED}.{BLOCKED}.212.79:443
• http://{BLOCKED}.{BLOCKED}.192.45:8080
• http://{BLOCKED}.{BLOCKED}.131.20:8080
• http://{BLOCKED}.{BLOCKED}.33.200:8080

It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

As of this writing, the said sites are inaccessible.

Other Details

This Trojan Spy does the following:

• It will create a startup service if it has admin privileges, otherwise it will only create an autorun entry in the registry.

It deletes the initially executed copy of itself

NOTES:
Information Theft

This Trojan Spy gathers the following data: