Analysis by: John Kevin Sanchez
ALIASES:

Trojan.MSIL.Agent (Ikarus), Trojan:Win32/Skeeyah.A!bit (Microsoft), Msil.Trojan.Agent.Dvzs (Tencent)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • 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.

It uses Windows Task Scheduler to create a scheduled task that executes the dropped copy.

It connects to certain websites to send and receive information.

  TECHNICAL DETAILS

File Size: 109,568 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 08 Aug 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:

  • %ProgramData%\UpdateService\UpdateService.exe
  • %All Users Profile%\UpdateService\UpdateService.exe

(Note: %ProgramData% is the Program Data folder, where it usually is C:\Program Files in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData in 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.. %All Users Profile% is the All Users folder, where it usually is C:\Documents and Settings\All Users on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData 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:

  • %ProgramData%\UpdateService\UpdateService.exe.config
  • %ProgramData%\UpdateService\settings.dat
  • %All Users Profile%\UpdateService\UpdateService.exe.config
  • %All Users Profile%\UpdateService\settings.dat
  • %System%\Tasks\UpdateService ← scheduled task

(Note: %ProgramData% is the Program Data folder, where it usually is C:\Program Files in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData in 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.. %All Users Profile% is the All Users folder, where it usually is C:\Documents and Settings\All Users on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData 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.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

It adds the following processes:

  • %ProgramData%\UpdateService\UpdateService.exe
  • "%System%\schtasks.exe" /Delete /TN "UpdateService" /F;
  • "%System%\schtasks.exe" /Create /RU SYSTEM /SC ONSTART /TN "UpdateService" /TR "\"C:\ProgramData\UpdateService\UpdateService.exe\" -t
  • "%System%\schtasks.exe" /Run /TN "UpdateService"
  • taskeng.exe %ProgramData%\UpdateService\UpdateService.exe -t
  • "%Windows%\Microsoft.NET\Framework\v2.0.50727\csc.exe" /noconfig /fullpaths @"%AppDataLocal%\Temp\{random}.cmdline"

(Note: %ProgramData% is the Program Data folder, where it usually is C:\Program Files in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData in 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.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %AppDataLocal% is the Application Data folder found in Local Settings, where it is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local 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 uses Windows Task Scheduler to create a scheduled task that executes the dropped copy.

It creates the following folders:

  • %ProgramData%\UpdateService
  • %All Users Profile%\UpdateService

(Note: %ProgramData% is the Program Data folder, where it usually is C:\Program Files in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData in 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.. %All Users Profile% is the All Users folder, where it usually is C:\Documents and Settings\All Users on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData 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 adds the following mutexes to ensure that only one of its copies runs at any one time:

  • Global\CLR_CASOFF_MUTEX
  • Global\d3091c53-b5db-4e3a-a345-c8a648bd6f1b
  • Global\.net clr networking

Autostart Technique

The scheduled task executes the malware every:

  • At every startup

Other Details

This Trojan connects to the following website to send and receive information:

  • http://{BLOCKED}.118.135/system/info.php?url=/update/check
  • http://{BLOCKED}.118.135/system/log.php?url=/update/check
  • http://{BLOCKED}defincas.org/wp-includes/class-wp-info.php?url=/update/check
  • http://{BLOCKED}defincas.org/wp-includes/class-wp-log.php?url=/update/check
  • http://{BLOCKED}ans.com/Nueva/kickstart/plugins/system/{BLOCKED}/content_log.php?url=/update/check
  • http://{BLOCKED}ka.ru/administrator/components/com_k2/views/settings/content_log.php?url=/update/check
  • http://{BLOCKED}.ru/administrator/{BLOCKED}/com_sh404sef/{BLOCKED}/wizard/content_log.php?url=/update/check
  • http://{BLOCKED}.co.uk/wp-includes/info.php?url=/update/check
  • http://{BLOCKED}.co.uk/wp-includes/log.php?url=/update/check
  • http://beta.{BLOCKED}.com/cg-bn/content_log.php?url=/update/check
  • http://beta.{BLOCKED}.com/cg-bn/modules_info.php?url=/update/check
  • http://{BLOCKED}.ru/{BLOCKED}/logs/info.php?url=/update/check
  • http://{BLOCKED}.ru/{BLOCKED}/logs/log.php?url=/update/check
  • http://{BLOCKED}-club.com/wp-{BLOCKED}/js/{BLOCKED}/plugins/wpeditimage/content_log.php?url=/update/check
  • http://{BLOCKED}.com.ua/image/cache/data/kuvez/reanimationplace/content_log.php?url=/update/check
  • http://{BLOCKED}.com.ua/image/cache/data/kuvez/reanimationplace/modules_info.php?url=/update/check
  • http://{BLOCKED}.com/administrator/components/com_akeeba/language/nb-NO/content_log.php?url=/update/check
  • http://{BLOCKED}.net/wp-content/plugins/all-in-one-wp-security-and-firewall/admin/general/content_log.php?url=/update/check
  • http://{BLOCKED}.codafarm.com/lvg/lbkgf/e8df/robiw/papkr342/content_log.php?url=/update/check
  • http://{BLOCKED}dia.{BLOCKED}.com/lvg/lbkgf/e8df/robiw/papkr342/modules_info.php?url=/update/check
  • http://{BLOCKED}-trunk.de/templates/{BLOCKED}/html/com_content/featured/content_log.php?url=/update/check
  • http://clearsky{BLOCKED}.com/administrator/{BLOCKED}/com_contenthistory/views/history/content_log.php?url=/update/check
  • http://{BLOCKED}-online.de/vertrieb/{BLOCKED}/o2/Data/content_log.php?url=/update/check
  • http://cop{BLOCKED}.hu/plugins/{BLOCKED}/logout/info.php?url=/update/check
  • http://cop{BLOCKED}.hu/plugins/{BLOCKED}/logout/log.php?url=/update/check
  • http://desire{BLOCKED}.com/fs8474v/pagesp{BLOCKED}/content_log.php?url=/update/check
  • http://{BLOCKED}den.se/wp-includes/js/tinymce/plugins/wpdialogs/js/info.php?url=/update/check
  • http://{BLOCKED}den.se/wp-includes/js/tinymce/plugins/wpdialogs/js/log.php?url=/update/check
  • http://evil{BLOCKED}.org/wp-includes/js/tinymce/plugins/lists/content_log.php?url=/update/check
  • http://{BLOCKED}orth.com/info?url=/update/check
  • http://{BLOCKED}orth.com/log?url=/update/check
  • http://f{BLOCKED}s.dp.ua/js/modules/{BLOCKED}/plugins/clipboard/content_log.php?url=/update/check
  • http://gesundheits{BLOCKED}-suhl.de/administrator/{BLOCKED}/com_xcloner-backupandrestore/classes/phpseclib/content_log.php?url=/update/check
  • http://{BLOCKED}andtyler.com/cg-bn/content_log.php?url=/update/check
  • http://holli{BLOCKED}.com/cg-bn/modules_info.php?url=/update/check
  • http://{BLOCKED}-voin.ru/wp-info.php?url=/update/check
  • http://{BLOCKED}-voin.ru/wp-log.php?url=/update/check
  • http://{BLOCKED}.org.ua/cgi-bin/content_log.php?url=/update/check
  • http://{BLOCKED}.org.ua/cgi-bin/modules_info.php?url=/update/check
  • http://jf-{BLOCKED}.de/components/com_weblinks/views/form/tmpl/content_log.php?url=/update/check
  • http://mebel-{BLOCKED}.com.ua/wp-admin/wp-info.php?url=/update/check
  • http://mebel-{BLOCKED}.com.ua/wp-admin/wp-log.php?url=/update/check
  • http://narko{BLOCKED}.ru/templates/beez3/html/com_contact/contact/content_log.php?url=/update/check
  • http://{BLOCKED}-nvkz.ru/administrator/components/com_menus/views/items/content_log.php?url=/update/check
  • http://{BLOCKED}.dinkumnet.com/w/wp-content/themes/twentysixteen/inc/content_log.php?url=/update/check
  • http://podaro{BLOCKED}.ru/admin/servis/sale/info.php?url=/update/check
  • http://podaro{BLOCKED}.ru/admin/servis/sale/log.php?url=/update/check
  • http://print{BLOCKED}.ru/bitrix/js/main/amcharts/3.0/content_log.php?url=/update/check
  • http://pro{BLOCKED}.at/sites/all/modules/mailchimp/modules/content_log.php?url=/update/check
  • http://prodam-{BLOCKED}.by/mmm/wp-content/plugins/Ultimate_VC_Addons/languages/content_log.php?url=/update/check
  • http://{BLOCKED}.ru/components/{BLOCKED}/templates/default/order/content_log.php?url=/update/check
  • http://reklama-{BLOCKED}.ru/components/{BLOCKED}/views/comment/tmpl/content_log.php?url=/update/check
  • http://ru{BLOCKED}.com/administrator/components/com_templates/views/source/content_log.php?url=/update/check
  • http://strategisk{BLOCKED}ledelse.dk/wp-content/{BLOCKED}/info.php?url=/update/check
  • http://strategisk{BLOCKED}ledelse.dk/wp-content/{BLOCKED}/log.php?url=/update/check
  • http://{BLOCKED}-sas.ru/templates/jsn_epic_free/html/com_wrapper/wrapper/content_log.php?url=/update/check
  • http://{BLOCKED}.com.ua/{BLOCKED}/ie/log.php?url=/update/check
  • http://{BLOCKED}.com.ua/{BLOCKED}/ie/style.php?url=/update/check
  • http://{BLOCKED}pub.com/!{BLOCKED}/zkt/lbkgf/vgu/content_log.php?url=/update/check
  • http://www.{BLOCKED}bwin.com/uf666/plugins/bower_components/jquery/dist/content_log.php?url=/update/check
  • http://www.es{BLOCKED}s.com/{BLOCKED}/content_log.php?url=/update/check
  • http://{BLOCKED}.ru/libraries/cms/schema/{BLOCKED}/info.php?url=/update/check
  • http://{BLOCKED}.ru/libraries/cms/schema/{BLOCKED}/log.php?url=/update/check

NOTES:

It uses different command lines to trigger behavior:

  • -t = create and run schedule task
  • -u = create autorun registry entry
    • HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
      • UpdateService= %ProgramData%\UpdateService\UpdateService.exe
  • -r and -i = drop the following components:
    • %AppDataLocal%\Temp\{random filename}.out
    • %AppDataLocal%\Temp\{random filename}.err
    • %AppDataLocal%\Temp\{random filename}.dll
    • %AppDataLocal%\Temp\{random filename}.tmp
    • %AppDataLocal%\Temp\{random filename}.0.cs
    • %AppDataLocal%\Temp\{random filename}.cmdline

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.586.06
FIRST VSAPI PATTERN DATE: 10 Aug 2017
VSAPI OPR PATTERN File: 13.587.00
VSAPI OPR PATTERN Date: 11 Aug 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

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\CurrentVersion\Run
    • UpdateService = "%ProgramData%\UpdateService\UpdateService.exe"

Step 4

Deleting Scheduled Tasks

For Windows 2000, Windows XP, and Windows Server 2003:

  1. Open the Windows Scheduled Tasks. Click Start>Programs>Accessories>
    System Tools>Scheduled Tasks.
  2. Locate each task that has the following value in the Schedule column:
    • UpdateService
  3. Right-click on the said file(s) with the aforementioned value.
  4. Click on Properties. In the Run field, check for the following string:
    Cmd /c /rd /s /q C:
  5. If the said string is found, delete the task.

For Windows Vista, Windows 7, Windows Server 2008, Windows 8, Windows 8.1, and Windows Server 2012:

  1. Open the Windows Task Scheduler. To do this:
    • On Windows Vista, Windows 7, and Windows Server 2008, click Start, type taskschd.msc in the Search input field, then press Enter.
    • On Windows 8, Windows 8.1, and Windows Server 2012, right-click on the lower left corner of the screen, click Run, type taskschd.msc, then press Enter.
  2. In the left panel, click Task Scheduler Library.
  3. In the upper-middle panel, locate each task that has the value in the Triggers column:
    • UpdateService
  4. In the lower-middle panel, click the Actions tab. In the Details column, check for the following string:
    Cmd /c /rd /s /q C:
  5. If the said string is found, delete the task..

Step 5

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.
  • %ProgramData%\UpdateService
  • %All User Profile%\UpdateService

Step 6

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.
  • %System%\Tasks\UpdateService

Step 7

Scan your computer with your Trend Micro product to delete files detected as TROJ_COINMINE.WIPC. 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.


Did this description help? Tell us how we did.