ALIASES:

TrojanSpy:MSIL/Omaneat.A (Microsoft); W32/Worm-FSD!Gamarue (McAfee); Backdoor.Win32.Androm.hena (Kaspersky); Mal/MSIL-OM (Sophos); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse MSIL8.XTF (AVG)

 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • 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

File Size: 377,344 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 11 Jul 2015

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 copies of itself into the affected system:

  • %System Root%\995246\update.exe

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

It creates the following folders:

  • %System Root%\995346
  • %System Root%\995246
  • %System Root%\995346\995247
  • %System Root%\995346\995248
  • %System Root%\995346\995249

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

Other System Modifications

This backdoor deletes the following files:

  • {malware path and file name}:zone.identifier
  • %System Root%\995246\update.exe:Zone.Identifier

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

It adds the following registry entries:

HKEY_CURRENT_USER\Software
uNtW+MidCtfWmmjP+JvOtQ== = "53XQQkG+8gUyT51I9ylwnw=="

HKEY_CURRENT_USER\Software
8GTQznn5sbdC0XlOyVfoQA== = "BGVBbi6be+JSp4mzXCScZA=="

Dropping Routine

This backdoor drops the following files:

  • %System Root%\755994bd2c85752c603d9e122729882d7b656923
  • %System Root%\995346\995249\1

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

Other Details

This backdoor connects to the following possibly malicious URL:

  • {BLOCKED}.128.150

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.750

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

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software
    • uNtW+MidCtfWmmjP+JvOtQ== = "53XQQkG+8gUyT51I9ylwnw=="
  • In HKEY_CURRENT_USER\Software
    • 8GTQznn5sbdC0XlOyVfoQA== = "BGVBbi6be+JSp4mzXCScZA=="

Step 3

Search and delete these components

[ Learn More ]
There may be some components that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %System Root%\755994bd2c85752c603d9e122729882d7b656923
  • %System Root%\995346\995249\1

Step 4

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %System Root%\995346
  • %System Root%\995246
  • %System Root%\995346\995247
  • %System Root%\995346\995248
  • %System Root%\995346\995249

Step 5

Scan your computer with your Trend Micro product to delete files detected as BKDR_ANDROM.YUYDE. 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.

Step 6

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • {malware path and file name}:zone.identifier
  • %System Root%\995246\update.exe:Zone.Identifier


Did this description help? Tell us how we did.