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TROJ_OTOTI.YAKU

June 12, 2017
 ALIASES:

TrojanSpy:MSIL/Omaneat.E (Microsoft); Trojan.Gen (Symantec); Trojan-Spy.MSIL.Omaneat.ecl (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse Autoit2_c.ASMG (AVG)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • 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.

  TECHNICAL DETAILS

File Size:

1,757,184 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

12 Jun 2017

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:

  • %Program Files%\svchost\svchost.exe

(Note: %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)

It creates the following folders:

  • %User Profile%\Application Data\4nVXx3qqsi
  • %User Profile%\Application Data\WinDir
  • %Program Files%\svchost
  • %User Profile%\WinDir\Logs
  • %User Profile%\WinDir\Files
  • %User Profile%\WinDir\Guard
  • %User Profile%\WinDir\Screenshots

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)

Other System Modifications

This Trojan deletes the following files:

  • %Program Files%\svchost\svchost.exe:Zone.Identifier

(Note: %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)

It adds the following registry entries:

HKEY_CURRENT_USER\Software
8QQ2a9YdYaB5dGC7KoEtdQ== = "qKDagoroo8p5qMTSxFNWaq+cf9E6oH8U+/jqCjCNXGQ="

HKEY_CURRENT_USER\Software
bt+DwZgV/xxgbG53r/8NPg== = "ftU/z/6aSjCKo1Tm/jxe1Q=="

HKEY_CURRENT_USER\Software
GzwRH+eaeExJWIEiHO7m9g== = "LyOUZXDAu3qMyQGPQUn1zA=="

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\aut4.tmp
  • %User Profile%\Guard\1
  • %User Temp%\V9x.m

(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.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • {BLOCKED}.98.61
  • {BLOCKED}8.1.51

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.8

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

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
    • 8QQ2a9YdYaB5dGC7KoEtdQ== = "qKDagoroo8p5qMTSxFNWaq+cf9E6oH8U+/jqCjCNXGQ="
  • In HKEY_CURRENT_USER\Software
    • bt+DwZgV/xxgbG53r/8NPg== = "ftU/z/6aSjCKo1Tm/jxe1Q=="
  • In HKEY_CURRENT_USER\Software
    • GzwRH+eaeExJWIEiHO7m9g== = "LyOUZXDAu3qMyQGPQUn1zA=="

Step 3

Search and delete these components

[ Learn More ]
There may be some components 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%\aut4.tmp
  • %User Profile%\Guard\1
  • %User Temp%\V9x.m

Step 4

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %User Profile%\Application Data\4nVXx3qqsi
  • %User Profile%\Application Data\WinDir
  • %Program Files%\svchost
  • %User Profile%\WinDir\Logs
  • %User Profile%\WinDir\Files
  • %User Profile%\WinDir\Guard
  • %User Profile%\WinDir\Screenshots

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_OTOTI.YAKU. 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 6

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %Program Files%\svchost\svchost.exe:Zone.Identifier


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