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TROJ_UPATRE.YYSKR

July 11, 2015
 Analysis by: Miguel Carlo Ang
 ALIASES:

TrojanDownloader:Win32/Upatre!rfn(Microsoft);Trojan-Downloader.Win32.Upatre.aqfl(Kaspersky);Win32/TrojanDownloader.Waski.F(ESET-NOD32)

 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, Dropped by other malware


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 deletes the file(s) associated with the process(es) it terminates. It does the said routine to completely disable programs and applications.

It executes downloaded files whose malicious routines are exhibited by the affected system.

It deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size:

49,152 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

11 Jul 2015

Payload:

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 drops the following copies of itself into the affected system and executes them:

  • %User Temp%\EyeIbin.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%\Ibin5D38.txt - temporary container of encrypted code and file

(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.)

Other System Modifications

This Trojan adds the following registry entries:

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows NT\CurrentVersion
kereruthjertr456 = 1

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows NT\CurrentVersion
WinNtM = 1 (if malwarebytes found in the system)

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows NT\CurrentVersion
WinNtE = 1 (if ESET found in the system)

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows NT\CurrentVersion
WinNtAv = 1 (if AVG found in the system)

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows NT\CurrentVersion
WinNtAr = 1 (if Avira found in the system)

Process Termination

This Trojan terminates the following processes if found running in the affected system's memory:

  • mbam.exe (Malwarebytes Anti-Malware)
  • ekrn.exe (ESET Smart Security)
  • avgui.exe (AVG User Interface)
  • avgnt.exe (Avira System Tray Tool)

It deletes the file(s) associated with the process(es) it terminates. It does the said routine to completely disable programs and applications.

Download Routine

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

  • {BLOCKED}.{BLOCKED}.221.89:443/status11.pdf
  • {BLOCKED}.{BLOCKED}.144.177:443/status11.pdf
  • {BLOCKED}.{BLOCKED}.22.227:443/status11.pdf
  • {BLOCKED}.{BLOCKED}.31.1:443/status11.pdf
  • {BLOCKED}.{BLOCKED}.31.6:443/status11.pdf
  • {BLOCKED}.{BLOCKED}.16.79:443/status11.pdf
  • {BLOCKED}.{BLOCKED}.107.12:443/status11.pdf
  • {BLOCKED}.{BLOCKED}.236.2:443/status11.pdf
  • {BLOCKED}.{BLOCKED}.167.4:443/status11.pdf
  • {BLOCKED}.{BLOCKED}.175.213:443/status11.pdf
  • {BLOCKED}.{BLOCKED}.27.163:443/status11.pdf
  • {BLOCKED}.{BLOCKED}.255.79:443/status11.pdf
  • {BLOCKED}.{BLOCKED}.24.114:443/status11.pdf
  • {BLOCKED}.{BLOCKED}.203.173:443/status11.pdf
  • {BLOCKED}.{BLOCKED}.239.34:443/status11.pdf

It saves the files it downloads using the following names:

  • %User Temp%\djurqajn.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 executes downloaded files :

  • %User Temp%\djurqajn.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.)

whose malicious routines are exhibited by the affected system.

Other Details

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

  • icanhazip.com

It does the following:

  • It connects to the following URLs to report infection of the affected system: http://{BLOCKED}.{BLOCKED}.194.101:13000/SATU11/{COMPUTER NAME}/41/2/{SERVICEPACK}/0/{RANDOM STRING}

It deletes the initially executed copy of itself

  SOLUTION

Minimum Scan Engine:

9.750

FIRST VSAPI PATTERN FILE:

11.708.07

FIRST VSAPI PATTERN DATE:

02 Jun 2015

VSAPI OPR PATTERN File:

11.709.00

VSAPI OPR PATTERN Date:

03 Jun 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

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

 
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows NT\CurrentVersion
    • kereruthjertr456 = 1
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows NT\CurrentVersion
    • WinNtM = 1 (if malwarebytes found in the system)
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows NT\CurrentVersion
    • WinNtE = 1 (if ESET found in the system)
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows NT\CurrentVersion
    • WinNtAv = 1 (if AVG found in the system)
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows NT\CurrentVersion
    • WinNtAr = 1 (if Avira found in the system)

Step 4

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%\Ibin5D38.txt

Step 5

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

    • TSPY_DYRE.YYSKR

Step 6

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