Analysis by: Clive Fuentebella
ALIASES:

Win32/TrojanDownloader.Delf.CZQ trojan (NOD32)

 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

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

Tamaño del archivo 646,144 bytes
Tipo de archivo EXE
Residente en memoria Yes
Fecha de recepción de las muestras iniciales 04 Nov 2020

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 drops the following files:

  • %User Temp%\IXP000.TMP\TMP4351$.TMP
  • %User Temp%\IXP000.TMP\DOCUMENT2.EXE
  • %AppDataLocal%\Microsoft\Windows\Inczdrv.exe
  • %AppDataLocal%\zcnI.url
  • %Application Data%\microsoftwndddows98\logs.dat

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It adds the following processes:

  • %User Temp%\IXP000.TMP\DOCUMENT2.EXE
  • %Program Files%\internet explorer\ieinstal.exe

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Other System Modifications

This Backdoor adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunOnce
wextract_cleanup0 = rundll32.exe %System%\advpack.dll,DelNodeRunDLL32 "%User Temp%\IXP000.TMP\"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Incz = %AppDataLocal%\zcnI.url

HKEY_CURRENT_USER\Software\microsoftwndddows98-Q8G3TQ
exepath = T\xd1

HKEY_CURRENT_USER\Software\microsoftwndddows98-Q8G3TQ
licence = 23121EFCD91EE2385BE3F8ABABB805B3

Other Details

This Backdoor connects to the following possibly malicious URL:

  • style.{BLOCKED}sps.co.id