TROJ_UPATRE.HJ

April 20, 2015
 Analysis by: Homer Pacag
 ALIASES:

TrojanDownloader:Win32/Upatre.AZ(Microsoft);Troj/Mdrop-GPM(Sophos);

 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:

Spammed via email, Downloaded from the Internet

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.

It deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size:

51,712 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

07 Apr 2015

Payload:

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 copies of itself into the affected system and executes them:

  • %User Temp%\nlibzar.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 drops the following files:

  • %User Temp%\bwtBBCB.tmp

(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.)

Download Routine

This Trojan accesses the following websites to download files:

  • http://{BLOCKED}rosonline.net/wp-includes/css/mandoc1.pdf
  • http://{BLOCKED}mis.com/mandoc1.pdf
  • http://{BLOCKED}mis.com/cgi-sys/suspendedpage.cgi

It saves the files it downloads using the following names:

  • %Windows%\{random}.exe

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

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

Other Details

This Trojan connects to the following URL(s) to get the affected system's IP address:

  • http://checkip.dyndns.org

It deletes the initially executed copy of itself

NOTES:

It also accesses the following URL before download:

  • {BLOCKED}1.{BLOCKED}5.141.87:13895/0704uk11/{COMPUTER NAME}/0/{OS VERSION}/0/{ENCRYPTED IP}
  • {BLOCKED}1.{BLOCKED}5.141.87:13895/0704uk11/{COMPUTER NAME}/41/2/{ServicePack}/0/{ENCRYPTED IP}

  SOLUTION

Minimum Scan Engine:

9.750

FIRST VSAPI PATTERN FILE:

11.588.05

FIRST VSAPI PATTERN DATE:

07 Apr 2015

VSAPI OPR PATTERN File:

11.589.00

VSAPI OPR PATTERN Date:

07 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

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%\nlibzar.exe
  • %User Temp%\bwtBBCB.tmp
  • %Windows%\{random}.exe

Step 4

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


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