TROJ_UPATRE.AAJ

 Analysis by: Mark Joseph Manahan

 ALIASES:

Trojan.Win32.Bublik.bpvi (Kaspersky), Trojan.Zbot (Symantec)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW


This Trojan 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.

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

  TECHNICAL DETAILS

File Size:

12,288 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

24 Dec 2013

Arrival Details

This Trojan 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 Trojan drops the following copies of itself into the affected system:

  • %User Temp%\operaupdater.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, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

It executes then deletes itself afterward.

Download Routine

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

  • https://{BLOCKED}dies.org.uk/wp-content/uploads/et_temp/pdf.exe - detected as TSPY_ZBOT.AAJ
  • https://{BLOCKED}s.com/{BLOCKED}iphoneunlockiphone.com/images/pdf.exe - detected as TSPY_ZBOT.AAJ

It saves the files it downloads using the following names:

  • %User Temp%\zijer.exe - detected as TSPY_ZBOT.AAJ

(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, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

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

  SOLUTION

Minimum Scan Engine:

9.700

FIRST VSAPI PATTERN FILE:

10.498.01

FIRST VSAPI PATTERN DATE:

25 Dec 2013

VSAPI OPR PATTERN File:

10.499.00

VSAPI OPR PATTERN Date:

26 Dec 2013

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Remove malware/grayware files dropped/downloaded by TROJ_UPATRE.AAJ

  • TSPY_ZBOT.AAJ

Step 3

Scan your computer with your Trend Micro product to delete files detected as TROJ_UPATRE.AAJ. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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