Analysis by: Byron Jon Gelera
ALIASES:

a variant of Win32/MailRu.D potentially unwanted (NOD32); W32/Generic_PUA_PP.D (Fortinet)

 PLATFORM:

Windows

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

  • Threat Type: Potentially Unwanted Application

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Potentially Unwanted Application arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites. It may be manually installed by a user.

  TECHNICAL DETAILS

File Size: 2,293,432 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 19 Feb 2018

Arrival Details

This Potentially Unwanted Application arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It may be manually installed by a user.

Installation

This Potentially Unwanted Application adds the following folders:

  • %AppDataLocal%\Mail.Ru

(Note: %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 drops the following copies of itself into the affected system:

  • %AppDataLocal%\Mail.Ru\Sputnik\ptls\mailruhomesearch.exe

(Note: %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 drops the following files:

  • %All Users Profile%\Mail.Ru\Id
  • %Application Data%\Microsoft\Internet Explorer\Quick Launch\Mail.Ru.lnk
  • %Application Data%\Microsoft\Internet Explorer\Quick Launch\User Pinned\TaskBar\Mail.Ru.lnk
  • %Desktop%\Искать в Интернете.url
  • %AppDataLocal%\Mail.Ru\GoMailRu.ico
  • %AppDataLocal%\Mail.Ru\Sputnik\MailRu.ico
  • %AppDataLocal%\Mail.Ru\Tmp\DeferredTasks\{3654EFDD-A46C-4CFC-BA58-A00F1723D1BD}_c
  • %AppDataLocal%\Mail.Ru\Tmp\DeferredTasks\metadata
  • %AppDataLocal%\Mail.Ru\Tmp\DeferredTasks\{3654EFDD-A46C-4CFC-BA58-A00F1723D1BD}\p4273e8235f07a4c6720af0c5e30391cd
  • %AppDataLocal%\Mail.Ru\Tmp\DeferredTasks\{3654EFDD-A46C-4CFC-BA58-A00F1723D1BD}\p3f74b09470540b97739f3bdde65e75f8
  • %AppDataLocal%\Mail.Ru\Tmp\DeferredTasks\{3654EFDD-A46C-4CFC-BA58-A00F1723D1BD}\p16d0f0c86e1a9125219bb1c863df0572
  • %AppDataLocal%\Mail.Ru\Tmp\DeferredTasks\{2A098EFB-0F0A-42D1-ACBD-F56EED080A45}_c
  • %AppDataLocal%\Mail.Ru\Tmp\DeferredTasks\{2A098EFB-0F0A-42D1-ACBD-F56EED080A45}\p6d2c7cda72cc50d7cd4d37c62f194afa
  • %AppDataLocal%\Mail.Ru\Tmp\DeferredTasks\{2A098EFB-0F0A-42D1-ACBD-F56EED080A45}\pfe58101a796f702a65f3b942494e7d1b
  • %AppDataLocal%\Mail.Ru\Tmp\DeferredTasks\{2A098EFB-0F0A-42D1-ACBD-F56EED080A45}\p87b6ef4d2807d48bd2cd8d0ee8037ba6
  • %AppDataLocal%\Mail.Ru\mrkeeper.exe

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

Autostart Technique

This Potentially Unwanted Application adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
mailruhomesearch = "%AppDataLocal%\Mail.Ru\Sputnik\ptls\mailruhomesearch.exe" --pr_deferred

Other System Modifications

This Potentially Unwanted Application adds the following registry keys:

HKEY_CURRENT_USER\Software\Mail.Ru\
Tech

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
MailRuUpdater

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Updater.Mail.Ru

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Mail.Ru\
Tech
UserID = {User ID}

HKEY_CURRENT_USER\Software\Mail.Ru\
Tech\ExternalES\ie\
{8E8F97CD-60B5-456F-A201-73065652D099}
(Default) = {JSON data}

HKEY_CURRENT_USER\Software\Mail.Ru\
Tech
avedte = {hex value}

HKEY_CURRENT_USER\Software\Mail.Ru\
Tech\ExternalES\ch\
lhemechcanjmilllmccjbjldonmnnjjj
(Default) = {hex value}

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
MailRuUpdater
UninstallString = "%AppDataLocal%\Mail.Ru\MailRuUpdater.exe uninstall

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
MailRuUpdater
DisplayName = ?????? ??????????????? ?????????? ????????

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
MailRuUpdater
Publisher = Mail.Ru

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
MailRuUpdater
DisplayIcon = "%AppDataLocal%\Mail.Ru\MailRuUpdater.exe

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
MailRuUpdater
InstallLocation = "%AppDataLocal%\Mail.Ru\MailRuUpdater.exe

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
MailRuUpdater
VersionMajor = 3

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
MailRuUpdater
VersionMinor = 14

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Updater.Mail.Ru
ObjectName = LocalSystem

HKEY_CURRENT_USER\Software\Mail.Ru\
Tech\ptls\{84DC8324-C256-4EF5-B0DC-383B43EE77E9}\
ready_items
waiter = 1

HKEY_CURRENT_USER\Software\Mail.Ru\
Tech\ptls\{C6011285-FAD0-4FF2-9C8F-49B3F1CC564D}
finished_time = {time}

HKEY_CURRENT_USER\Software\Mail.Ru\
Tech\ptls\{4947360E-E26B-4CC9-BB40-F4A30EDCA39E}
runid = 10

HKEY_CURRENT_USER\Software\Mail.Ru\
Tech\ptls\{FC604959-8A01-4E8B-A3E5-87CEEBD6FEDB}
finished_time = {time}

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
MailRuUpdater = "%AppDataLocal%\Mail.Ru\MailRuUpdater.exe

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Updater.Mail.Ru
Type = 16

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Updater.Mail.Ru
Start = 2

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Updater.Mail.Ru
ErrorControl = 0

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Updater.Mail.Ru
ImagePath = %Program Files%\Mail.Ru\MailRuUpdater\MailRuUpdater.exe --s

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Updater.Mail.Ru
DisplayName = Updater.Mail.Ru

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Updater.Mail.Ru
Description = ???????????? ?????????? ????????? ???????? Mail.Ru Group (?????? 3.14.0.50)

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Start Page = "http://{BLOCKED}l.ru/cnt/10445?gp="

(Note: The default value data of the said registry entry is {user defined}.)

Other Details

This Potentially Unwanted Application connects to the following possibly malicious URL:

  • http://mrds.{BLOCKED}l.ru/update/2/version.txt?type={value}&bgn={value}&standalone={value}&masterid={value}&user_id={value}&osver={value}&osbit={value}&osvernum={value}&ossp={value}&uac={value}&admin={value}&ver={value}&mailru_guard={value}&mailru_updater={value}&comp_mem={value}&tool_mem={value}&elapsed_time={value}&mr_service={value}&os={value}&tool={value}&GUID={value}&common_rfr={value}&install_id={value}&rfr_rules=
  • http://mrds.{BLOCKED}l.ru/update/2/version.txt?type={value}&br={value}&sjs_readed={value}&sjs_exists={value}&sjs_check={value}&masterid={value}&user_id={value}&osver={value}&osbit={value}&osvernum={value}&ossp={value}&uac={value}&admin={value}&ver={value}&mailru_guard={value}&mailru_updater={value}&comp_mem={value}&tool_mem={value}&elapsed_time={value}&mr_service={value}&os={value}&tool={value}&GUID={value}&common_rfr={value}&install_id={value}&rfr_rules=
  • http://mrds.{BLOCKED}l.ru/update/2/version.txt?type={value}&elevated={value}&h_secpref={value}&ch_sync_settings={value}&ch_sync_ext={value}&masterid={value}&user_id={value}&osver={value}&osbit={value}&osvernum={value}&ossp={value}&uac={value}&admin={value}&ver={value}&mailru_guard={value}&mailru_updater={value}&comp_mem={value}&tool_mem={value}&elapsed_time={value}&mr_service={value}&os={value}&tool={value}&GUID={value}&common_rfr={value}&install_id={value}&rfr_rules=
  • http://mrds.{BLOCKED}l.ru/update/2/version.txt?type={value}&id={value}&event={value}&masterid={value}&user_id={value}&osver={value}&osbit={value}&osvernum={value}&ossp={value}&uac={value}&admin={value}&ver={value}&mailru_guard={value}&mailru_updater={value}&comp_mem={value}&tool_mem={value}&elapsed_time={value}&mr_service={value}&os={value}&tool={value}&GUID={value}&common_rfr={value}&install_id={value}&rfr_rules=
  • http://mrds.{BLOCKED}l.ru/update/2/version.txt?type={value}&paid_action={value}&paid_browser={value}&br={value}&comp={value}&pay_browser_class={value}&install_browser_class={value}&rfr={value}&br_default={value}&browser_class1={value}&browser_class2={value}&extid={value}&masterid={value}&user_id={value}&osver={value}&osbit={value}&osvernum={value}&ossp={value}&uac={value}&admin={value}&ver={value}&mailru_guard={value}&mailru_updater={value}&comp_mem={value}&tool_mem={value}&elapsed_time={value}&mr_service={value}&os={value}&tool={value}&GUID={value}&common_rfr={value}&install_id={value}&rfr_rules={value}&rand={value}&randh={value}&chrome_ud={value}
  • http://mrds.{BLOCKED}l.ru/update/2/version.txt?type={value}&raw={value}&masterid={value}&user_id={value}&osver={value}&osbit={value}&osvernum={value}&ossp={value}&uac={value}&admin={value}&ver={value}&mailru_guard={value}&mailru_updater={value}&comp_mem={value}&tool_mem={value}&elapsed_time={value}&mr_service={value}&os={value}&tool={value}&GUID={value}&common_rfr={value}&install_id={value}&rfr_rules=
  • http://mrds.{BLOCKED}l.ru/update/2/version.txt?type={value}&success={value}&br={value}&masterid={value}&user_id={value}&osver={value}&osbit={value}&osvernum={value}&ossp={value}&uac={value}&admin={value}&ver={value}&mailru_guard={value}&mailru_updater={value}&comp_mem={value}&tool_mem={value}&elapsed_time={value}&mr_service={value}&os={value}&tool={value}&GUID={value}&common_rfr={value}&install_id={value}&rfr_rules=
  • http://mrds.{BLOCKED}l.ru/update/2/version.txt?type={value}&target={value}&prog={value}&event={value}&mr_ext={value}&masterid={value}&user_id={value}&osver={value}&osbit={value}&osvernum={value}&ossp={value}&uac={value}&admin={value}&ver={value}&mailru_guard={value}&mailru_updater={value}&comp_mem={value}&tool_mem={value}&elapsed_time={value}&mr_service={value}&os={value}&tool={value}&GUID={value}&common_rfr={value}&install_id={value}&rfr_rules=
  • http://mrds.{BLOCKED}l.ru/update/2/version.txt?type={value}&target={value}&prog={value}&masterid={value}&user_id={value}&osver={value}&osbit={value}&osvernum={value}&ossp={value}&uac={value}&admin={value}&ver={value}&mailru_guard={value}&mailru_updater={value}&comp_mem={value}&tool_mem={value}&elapsed_time={value}&mr_service={value}&os={value}&tool={value}&GUID={value}&common_rfr={value}&install_id={value}&rfr_rules=

  SOLUTION

Minimum Scan Engine: 9.850
SSAPI PATTERN File: 1.921.00
SSAPI PATTERN Date: 22 Feb 2018

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 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\Mail.Ru
    • Tech
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall
    • MailRuUpdater
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services
    • Updater.Mail.Ru

Step 4

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
    • mailruhomesearch = "%AppDataLocal%\Mail.Ru\Sputnik\ptls\mailruhomesearch.exe" --pr_deferred
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • MailRuUpdater = "%AppDataLocal%\Mail.Ru\MailRuUpdater.exe

Step 5

Search and delete this folder

[ 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. %AppDataLocal%\Mail.Ru
  • %AppDataLocal%\Mail.Ru

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.
  • %Desktop%\Искать в Интернете.url
  • %All Users Profile%\Mail.Ru\Id
  • %Application Data%\Microsoft\Internet Explorer\Quick Launch\Mail.Ru.lnk
  • %Application Data%\Microsoft\Internet Explorer\Quick Launch\User Pinned\TaskBar\Mail.Ru.lnk

Step 7

Restore this modified 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\Internet Explorer\Main
    • From: Start Page = http://mail.ru/cnt/10445?gp=
      To: Start Page = {user defined}

Step 8

Scan your computer with your Trend Micro product to delete files detected as PUA_MAILRU.GA. 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 the following Trend Micro Support pages for more information:


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