Analysis by: John Kevin Sanchez

ALIASES:

Trojan-Downloader.Win32.Injecter.ung (Kaspersky), Trojan.Win32.Injecter.ephimg (NANO-Antivirus)

 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 malware is part of the malware spam attack Trend Micro uncovered early June of 2017, one that targeted certain organizations in the EMEA region through the abuse of the mouse hover action to deliver malware. This is the payload of that attack.

This Trojan may be downloaded by other malware/grayware from remote sites.

It modifies the Internet Explorer Zone Settings.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size: 237,568 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 27 May 2017
Payload: Drops files, Modifies system registry

Arrival Details

This Trojan may be downloaded by the following malware/grayware from remote sites:

Installation

This Trojan drops the following copies of itself into the affected system:

  • %Application Data%\Microsoft\Internet Explorer\{filename}.exe
    where {filename} is any name of .exe file in %System% folder

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

It drops the following files:

  • %Application Data%\Microsoft\Internet Explorer\{filename}.inf
    where {filename} is any name of .exe file in %System% folder
  • {malware path}\{random numbers}.bat - use to delete the malware

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

It adds the following processes:

  • mstsc.exe

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • ServiceEntryPointThread

It injects codes into the following process(es):

  • mstsc.exe

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
IEAK

HKEY_CURRENT_USER\Software\Microsoft\
IEAK\GroupPolicy

HKEY_CURRENT_USER\Software\Microsoft\
IEAK\GroupPolicy\PendingGPOs

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft
CtrlLogMaxSize = 0xd05

HKEY_LOCAL_MACHINE\Software\Microsoft
CtrlLogMaxSize = 0xd05

HKEY_CURRENT_USER\Software\Microsoft\
IEAK\GroupPolicy\PendingGPOs
Count = 1

HKEY_CURRENT_USER\Software\Microsoft\
IEAK\GroupPolicy\PendingGPOs
Path1 = %Application Data%\Microsoft\Internet Explorer\icapoq.inf

HKEY_CURRENT_USER\Software\Microsoft\
IEAK\GroupPolicy\PendingGPOs
Section1 = DefaultInstall

Propagation

The said .INF file contains the following strings:

[Version]
signature = "$CHICAGO$"
AdvancedINF = 2.5, "You need a new version of advpack.dll"

[DefaultInstall]
RunPreSetupCommands =
tpdsyfxbnporewlfyxybdhirskgzuhxbubkp:2

[tpdsyfxbnporewlfyxybdhirskgzuhxbubkp]
%Application Data%\Microsoft\Internet Explorer\{filename}.exe

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.)

Web Browser Home Page and Search Page Modification

This Trojan modifies the Internet Explorer Zone Settings.

Other Details

This Trojan does the following:

  • Checks for environment variable, “crackmeololo”.
  • Checks if user name is “CurrentUser” or “Sandbox”
  • Checks if computer name is “Sandbox” or “7Silvia”
  • Checks for registry entry:
    key: HKEY_LOCAL_MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor\0
    value: ProcessorNameString -> Checks data if equal to “XEON”
  • Checks for registry entry:
    key: HKEY_LOCAL_MACHINE\HARDWARE\DESCRIPTION\System
    value: SystemBiosVersion -> Checks data if equal to either “QEMU”, “AMI ”, “BOCHS”, “VBOX”, “SMCI”, “INTEL - 6040000” or “FTNT-1”
  • Checks for registry entry:
    key: HKEY_LOCAL_MACHINE\HARDWARE\DESCRIPTION\System
    value: VideoBiosVersion -> Checks data if equal to “VirtualBox”
  • Checks for registry entry:
    key: HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion
    value: SystemBiosVersion -> Checks data if equal to either “55274-640-2673064-23950”, “76487-644-3177037-23510” or “76487-337-8429955-22614”

It deletes itself after execution.

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.454.05
FIRST VSAPI PATTERN DATE: 06 Jun 2017
VSAPI OPR PATTERN File: 13.455.00
VSAPI OPR PATTERN Date: 07 Jun 2017

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

Restart in Safe Mode

[ Learn More ]

Step 4

Delete this registry key

[ 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
    • IEAK

Step 5

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.
  • %Application Data%\Microsoft\Internet Explorer\{filename}.inf

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_OTLARD.TY. 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 7

Reset Internet security settings

[ Learn More ]


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