Analysis by: Cris Nowell Pantanilla
ALIASES:

Trojan-Downloader.Win32.Upatre.fgk (Kaspersky); Troj/Upatre-KB (Sophos); Downloader.Upatre!gen9 (Symantec)

 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

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 executes then deletes itself afterward.

  TECHNICAL DETAILS

File Size: 30,720 bytes
File Type: EXE
Initial Samples Received Date: 02 Apr 2015
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 executes then deletes itself afterward.

Other System Modifications

This Trojan adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion
marker_gjru_fbegrihlgm = "TRUE"

Download Routine

This Trojan accesses the following websites to download files:

  • http://{BLOCKED}ciodelmueble.com/css/zico3.rtf
  • http://{BLOCKED}utions.in/css/zico3.rtf

NOTES:

The Trojan decrypts the downloaded binary and saves them as the following files:

  • %User Temp%\tmp7D3D.log
  • %User Temp%\{letters}{2digits}.exe - detected as TSPY_DYRE.YUYBV
  • %User Temp%\temp15.pdf - normal PDF

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

It also accesses the following URLs to send information:

  • http://{BLOCKED}1.{BLOCKED}5.141.87:{random port}/0204us21/{HostName}/0/{OS Version}-{Service Pack}/0/{Data}
  • http://{BLOCKED}1.{BLOCKED}5.141.87:{random port}/0204us21/{HostName}/41/1/{Service Pack}/0/{Data}

The following information are posted:

  • Computer name
  • Operating system version
  • Service pack installed

  SOLUTION

Minimum Scan Engine: 9.750
FIRST VSAPI PATTERN FILE: 11.590.05
FIRST VSAPI PATTERN DATE: 08 Apr 2015
VSAPI OPR PATTERN File: 11.591.00
VSAPI OPR PATTERN Date: 09 Apr 2015

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

Remove the malware/grayware file dropped/downloaded by TROJ_UPATRE.SMCP. (Note: Please skip this step if the threat(s) listed below have already been removed.)

    TSPY_DYRE.YUYBV

Step 3

Scan your computer with your Trend Micro product to delete files detected as TROJ_UPATRE.SMCP. 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.

Step 4

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%\tmp7D3D.log
%User Temp%\temp15.pdf


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