Trojan.X97M.DLOADER.AUSRM

January 16, 2020
 ALIASES:

TrojanDropper:O97M/Obfuse.MI!MTB (Microsoft); RDN/Generic Dropper (McAfee); Troj/DocDrp-NW (Sophos); Trojan-Dropper:W97M/MaliciousDoc.A (FSecure)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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.

  TECHNICAL DETAILS

File Size:

282,112 bytes

File Type:

XLS

Memory Resident:

Yes

Initial Samples Received Date:

16 Jan 2020

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 creates the following folders:

  • %User Temp%\msohtmlclip1\01
  • %User Temp%\msohtmlclip1
  • %User Profile%\Application Data\Microsoft\Forms
  • %User Temp%\msohtmlclip

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

Other System Modifications

This Trojan adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Wow6432Node\Interface\{BEF6E003-A874-101A-8BBA-00AA00300CAB}
(Default) = ""

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Discardable\PostSetup\Component Categories\
{56FFCC30-D398-11D0-B2AE-00A0C908FA49}\Enum
Implementing = "{random characters}"

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\E2A6A100
  • %User Temp%\factory.xlsx
  • %Application Data%\map_studio1.dll
  • %User Profile%\Application Data\Microsoft\Forms\EXCEL.box
  • %User Temp%\factory.xlsx.zip
  • %User Temp%\oleObject1.bin
  • {malware file path and name}

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

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}-msoffice365.com

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.850

Step 1

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 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_LOCAL_MACHINE\SOFTWARE\Classes\Wow6432Node\Interface\{BEF6E003-A874-101A-8BBA-00AA00300CAB}
    • (Default) = ""
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Discardable\PostSetup\Component Categories\{56FFCC30-D398-11D0-B2AE-00A0C908FA49}\Enum
    • Implementing = "{random characters}"

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.
  • %User Temp%\E2A6A100
  • %User Temp%\factory.xlsx
  • %Application Data%\map_studio1.dll
  • %User Profile%\Application Data\Microsoft\Forms\EXCEL.box
  • %User Temp%\factory.xlsx.zip
  • %User Temp%\oleObject1.bin
  • {malware file path and name}

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.
  • %User Temp%\msohtmlclip1\01
  • %User Temp%\msohtmlclip1
  • %User Profile%\Application Data\Microsoft\Forms
  • %User Temp%\msohtmlclip

Step 5

Scan your computer with your Trend Micro product to delete files detected as Trojan.X97M.DLOADER.AUSRM. 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 the following Trend Micro Support pages for more information:


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