Analysis by: Arvin Roi Macaraeg

ALIASES:

Trojan:Win32/Dynamer!ac (MICROSOFT), Trojan-Spy.Win32.Zbot.wwhw (KASPERSKY)

 PLATFORM:

Windows

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

  • Threat Type: Trojan Spy

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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 deletes itself after execution.

  TECHNICAL DETAILS

File Size: 214,829 bytes
File Type: ZIP
Initial Samples Received Date: 05 Jul 2016

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 the following files:

  • %Application Data%\{Random Folder Name}\{Random Letters}.tmp
  • %Application Data%\{Random Folder Name}}\{Random Letters}.{Random Letters}
  • %User Temp%\{Random Characters}.bat -> Deleted Afterwards

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

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

  • %Application Data%\{Random Folder Name}\{Random Letters}.exe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, and 8.)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{Random Letters} = "%Application Data%\{Random Folder Name}\{random letters}.exe"

Other System Modifications

This Trojan Spy adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
{Random letters}
{Random Letters} = {Hex Characters}

Other Details

This Trojan Spy connects to the following possibly malicious URL:

  • http://{BLOCKED}ez.com/slim/server/file.php

It deletes itself after execution.