PUA.Win32.MailRu.GO

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.

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.

Installation

This Potentially Unwanted Application creates the following folders:

• %Application Data%\Microsoft\Internet Explorer\Quick Launch\User Pinned\ImplicitAppShortcuts
• %System%\GroupPolicy\User
• %Application Data%\Microsoft\Internet Explorer\Quick Launch
• %User Temp%\ed0a-2976-45a3-da19
• %All Users Profile%\Mail.Ru
• %Application Data%\Microsoft\Internet Explorer\Quick Launch\User Pinned
• %System%\GroupPolicy\Machine
• %AppDataLocal%\Mail.Ru
• %AppDataLocal%\Mail.Ru\Sputnik

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

Other System Modifications

This Potentially Unwanted Application deletes the following files:

• %Application Data%\Mozilla\Firefox\Profiles\lj5mikyj.default\search.json.mozlz4

(Note: %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).)

It adds the following registry keys:

HKEY_USERS\S-1-5-21-2407829820-1079796033-203259571-500\Software\
Mail.Ru\Tech

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Group Policy Objects\
{94F89C3D-BEB7-4DEB-8DDB-8689125055FC}User

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Group Policy Objects\
{94F89C3D-BEB7-4DEB-8DDB-8689125055FC}Machine

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Group Policy Objects\
{4C893730-2E39-46D2-95BC-46F0CFB2A341}User

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Group Policy Objects\
{4C893730-2E39-46D2-95BC-46F0CFB2A341}Machine

HKEY_USERS\S-1-5-21-2407829820-1079796033-203259571-500\SOFTWARE\
Microsoft\Internet Explorer\Approved Extensions

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Group Policy Objects\
{E7DEE4AC-5876-45A1-A5A3-9C4CE29F9D2E}User

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Group Policy Objects\
{E7DEE4AC-5876-45A1-A5A3-9C4CE29F9D2E}Machine

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Group Policy Objects\
{94FD00BC-D0F3-4418-B5D3-3D9A4B48A10C}User

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Group Policy Objects\
{94FD00BC-D0F3-4418-B5D3-3D9A4B48A10C}Machine

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Group Policy Objects\
{2DEA7CFC-9965-4FB1-A210-5FCE1BD6B9D0}User

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Group Policy Objects\
{2DEA7CFC-9965-4FB1-A210-5FCE1BD6B9D0}Machine

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Mail.Ru\
Tech
UserID = "{F9DF87A9-EF55-42D4-91AD-3156F716C173}"

HKEY_CURRENT_USER\Software\Mail.Ru\
Tech
avedte = "{random characters}"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Taskband
FavoritesResolve = "{random characters}"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Taskband
Favorites = "{random characters}"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Taskband
FavoritesChanges = "14"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Taskband
FavoritesVersion = "2"

Dropping Routine

This Potentially Unwanted Application drops the following files:

• %Application Data%\Microsoft\Internet Explorer\Quick Launch\User Pinned\TaskBar\Mail.Ru.lnk
• %Application Data%\Microsoft\Internet Explorer\Quick Launch\Mail.Ru.lnk
• %Favorites%\Mail.Ru.url
• %Desktop%\xd0\x98\xd1\x81\xd0\xba\xd0\xb0\xd1\x82\xd1\x8c \xd0\xb2 \xd0\x98\xd0\xbd\xd1\x82\xd0\xb5\xd1\x80\xd0\xbd\xd0\xb5\xd1\x82\xd0\xb5.url
• %All Users Profile%\Mail.Ru\Id
• %AppDataLocal%\Mail.Ru\Sputnik\MailRu.ico
• %Application Data%\Mozilla\Firefox\Profiles\lj5mikyj.default\prefs.js.tmp
• %AppDataLocal%\Mail.Ru\GoMailRu.ico
• %User Temp%\GoMailRu.ico
• %Application Data%\Mozilla\Firefox\Profiles\lj5mikyj.default\prefs.js
• %System%\GroupPolicy\gpt.ini
• %Favorites%\Mail.Ru \xd0\x90\xd0\xb3\xd0\xb5\xd0\xbd\xd1\x82 - \xd0\xb8\xd1\x81\xd0\xbf\xd0\xbe\xd0\xbb\xd1\x8c\xd0\xb7\xd1\x83\xd0\xb9 \xd0\xb4\xd0\xbb\xd1\x8f \xd0\xbe\xd0\xb1\xd1\x89\xd0\xb5\xd0\xbd\xd0\xb8\xd1\x8f!.url
• %User Temp%\MailRu.ico

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

Other Details

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

• http://mrds.{BLOCKED}l.ru/update/2/version.txt?{random characters}
• http://conserv.{BLOCKED}o.mail.ru
• http://xmlbinupdate.{BLOCKED}l.ru

This report is generated via an automated analysis system.