Adware.Win32.MailRu.AA

January 31, 2020
 ALIASES:

HEUR:AdWare.Win32.Machaer.gen (Kaspersky)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 REPORTED INFECTION:
 SYSTEM IMPACT RATING:
 INFORMATION EXPOSURE:

  • Threat Type: Adware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Adware 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:

5,873,880 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

31 Jan 2020

Arrival Details

This Adware 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 Adware creates the following folders:

  • %All Users Profile%\Mail.Ru
  • %System%\GroupPolicy\Machine
  • %System%\GroupPolicy\User

(Note: %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit). . %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

Other System Modifications

This Adware adds the following registry entries:

HKEY_CURRENT_USER\Software\AppDataLow\
Software\Mail.Ru\IE_Bar\
Settings
GUID = "{17E0B54C-4849-4634-B256-20C4F2B5DBFB}"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Mail.Ru\Updater
GUID = "{17E0B54C-4849-4634-B256-20C4F2B5DBFB}"

HKEY_CURRENT_USER\Software\Mail.Ru\
Tech
UserID = "{05933368-47A8-4049-9571-A143FA7F5582}"

Dropping Routine

This Adware drops the following files:

  • %User Temp%\mrutmp.exe
  • %User Temp%\5FC366BFDD8B49B8BD2B46C06DB2853A.html
  • %User Temp%\92F7F6302AAE4FE68F31E103E678E918.html
  • %Application Data%\Mozilla\Firefox\Profiles\lj5mikyj.default\places.sqlite-wal
  • %All Users Profile%\Mail.Ru\Id
  • %System%\GroupPolicy\gpt.ini
  • %User Temp%\E9A77E81D5714B449B59CBB43D521398.html
  • %User Temp%\3B8B8727EF9446A58AB74B2198691DF6.html
  • %User Temp%\98F486BEAB904BC19AA2F10802A3970E.html
  • %User Temp%\CAF376404C014C42AD72C805A01700FC.html
  • %User Temp%\502293A324D64978A7D3AFB0E3FA93EF.html
  • %User Temp%\56A9DFAB3FF440D68EA2A796B11310C6.html
  • %Application Data%\Mozilla\Firefox\Profiles\lj5mikyj.default\places.sqlite
  • %Application Data%\Mozilla\Firefox\Profiles\lj5mikyj.default\places.sqlite-shm
  • %User Temp%\74D609CA565847D8ABA7178528B1A816.html
  • %User Temp%\89556D0546744915BEBD45AD57826B93.html

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit). . %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.850

Step 1

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 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\AppDataLow\Software\Mail.Ru\IE_Bar\Settings
    • GUID = "{17E0B54C-4849-4634-B256-20C4F2B5DBFB}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Mail.Ru\Updater
    • GUID = "{17E0B54C-4849-4634-B256-20C4F2B5DBFB}"
  • In HKEY_CURRENT_USER\Software\Mail.Ru\Tech
    • UserID = "{05933368-47A8-4049-9571-A143FA7F5582}"

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%\mrutmp.exe
  • %User Temp%\5FC366BFDD8B49B8BD2B46C06DB2853A.html
  • %User Temp%\92F7F6302AAE4FE68F31E103E678E918.html
  • %Application Data%\Mozilla\Firefox\Profiles\lj5mikyj.default\places.sqlite-wal
  • %All Users Profile%\Mail.Ru\Id
  • %System%\GroupPolicy\gpt.ini
  • %User Temp%\E9A77E81D5714B449B59CBB43D521398.html
  • %User Temp%\3B8B8727EF9446A58AB74B2198691DF6.html
  • %User Temp%\98F486BEAB904BC19AA2F10802A3970E.html
  • %User Temp%\CAF376404C014C42AD72C805A01700FC.html
  • %User Temp%\502293A324D64978A7D3AFB0E3FA93EF.html
  • %User Temp%\56A9DFAB3FF440D68EA2A796B11310C6.html
  • %Application Data%\Mozilla\Firefox\Profiles\lj5mikyj.default\places.sqlite
  • %Application Data%\Mozilla\Firefox\Profiles\lj5mikyj.default\places.sqlite-shm
  • %User Temp%\74D609CA565847D8ABA7178528B1A816.html
  • %User Temp%\89556D0546744915BEBD45AD57826B93.html

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.
  • %All Users Profile%\Mail.Ru
  • %System%\GroupPolicy\Machine
  • %System%\GroupPolicy\User

Step 5

Scan your computer with your Trend Micro product to delete files detected as Adware.Win32.MailRu.AA. 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:


Did this description help? Tell us how we did.