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TROJ_OTOTI.YAJV

April 08, 2017
 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • 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.

  TECHNICAL DETAILS

File Size:

954,880 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

05 Apr 2017

Payload:

Drops 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 and executes the following files:

  • %Windows%\SetACL.exe - normal file (set attributes to Hidden)

    Notes: With the following parameters: "-on "HKLM\SOFTWARE\ESET\ESET Security\CurrentVersion\Info" -ot reg -actn clear -clr dacl,sacl -silent"

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

Other System Modifications

This Trojan adds the following registry keys as part of its installation routine:

HKEY_LOCAL_MACHINE\Software\ESET

It also creates the following registry entry(ies) as part of its installation routine:

HKEY_LOCAL_MACHINE\SOFTWARE\ESET\
ESET Security
FirstUse = 1

HKEY_LOCAL_MACHINE\SOFTWARE\ESET\
ESET Security\CurrentVersion\Info
PackageTag = 1620109144

HKEY_LOCAL_MACHINE\SOFTWARE\ESET\
ESET Security\CurrentVersion\Info
ScannerVersion = Open window for status.

HKEY_LOCAL_MACHINE\SOFTWARE\ESET\
ESET Security\CurrentVersion\IPlugins\
01000400\Profiles\@My profile
SelectedServer = autoselect

HKEY_LOCAL_MACHINE\SOFTWARE\ESET\
ESET Security\CurrentVersion\Plugins\
01000400\Settings
InstallTime = 1970/01/01 00:00:00

HKEY_LOCAL_MACHINE\SOFTWARE\ESET\
ESET Security\CurrentVersion\Plugins\
01000400\Settings
LastUpdateAttempt = 1970/01/01 00:00:00

HKEY_LOCAL_MACHINE\SOFTWARE\ESET\
ESET Security\CurrentVersion\Plugins\
01000400\Settings
LastUpdate = 1970/01/01 00:00:00

HKEY_LOCAL_MACHINE\SOFTWARE\ESET\
ESET Security\CurrentVersion\Plugins\
01000400\Settings
FailSafeServer = http://update.eset.com/eset_eval/

HKEY_LOCAL_MACHINE\SOFTWARE\ESET\
ESET Security\CurrentVersion\Plugins\
01000400\Settings
RegistrationType = 0

HKEY_LOCAL_MACHINE\SOFTWARE\ESET\
ESET Security\CurrentVersion\Plugins\
01000400\Settings
Registration = 1

HKEY_LOCAL_MACHINE\SOFTWARE\ESET\
ESET Security\CurrentVersion\LicenseInfo
ExpirationDate = 1970/01/01 00:00:00

HKEY_LOCAL_MACHINE\SOFTWARE\ESET\
ESET Security\CurrentVersion\LicenseInfo
TimeStamp = 1970/01/01 00:00:00

HKEY_LOCAL_MACHINE\SOFTWARE\ESET\
ESET Security\CurrentVersion\Plugins\
01000101\Profiles\@My profile
Autostart = 1

HKEY_LOCAL_MACHINE\SOFTWARE\ESET\
ESET Security\CurrentVersion\Plugins\
01000600\Profiles\@My profile
SelfdefenceEnabled = 1

It deletes the following registry keys:

HKEY_LOCAL_MACHINE\Software\ESET

Process Termination

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

  • egui.exe

Other Details

This Trojan does the following:

  • It check installed AV product by searching the following files:
    • %Program Files%\ESET\ESET NOD32 Antivirus\egui.exe
  • It executes the following commands:
    • @Comspec /c sc config ekrn start = disabled
    • @Comspec /c sc config ekrn start= auto
    • @Comspec /c net start ekrn
    • cmd.exe %Program Files%\ESET\ESET NOD32 Antivirus\ecmd.exe /update open

(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.)

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.320.03

FIRST VSAPI PATTERN DATE:

05 Apr 2017

VSAPI OPR PATTERN File:

13.321.00

VSAPI OPR PATTERN Date:

06 Apr 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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.

  • In HKEY_LOCAL_MACHINE\Software
    • ESET

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.  
  • %Windows%\SetACL.exe

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_OTOTI.YAJV. 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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