PE_VIRLOCK.I


 ALIASES:

Virus:Win32/Nabucur.C (Microsoft); W32/VirRansom.b (McAfee); Trojan.Gen (Symantec); Virus.Win32.PolyRansom.b (Kaspersky); W32/VirRnsm-C (Sophos); Virus.Win32.Nabucur.b (v) (Sunbelt); Trojan horse LockScreen.BO (AVG)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 REPORTED INFECTION:

  • Threat Type: File infector

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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

It deletes itself after execution.

  TECHNICAL DETAILS

File Size:

970,240 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

11 Jul 2015

Arrival Details

This file infector 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 file infector creates the following folders:

  • %User Profile%\yQcYMwsM
  • %User Profile%\tIYMsMcQ
  • %User Profile%\FcUwwsIY

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Autostart Technique

This file infector adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
sYQsIcUg.exe = "%User Profile%\yQcYMwsM\sYQsIcUg.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
vEMosMIE.exe = "%User Profile%\tIYMsMcQ\vEMosMIE.exe"

It modifies the following registry entries to ensure it automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Userinit = "%System%\userinit.exe,%User Profile%\tIYMsMcQ\vEMosMIE.exe,"

(Note: The default value data of the said registry entry is %Windows%\system32\userinit.exe,.)

Other System Modifications

This file infector deletes the following files:

  • aKUE.ico
  • %User Profile%\Default Pictures\airplane.bmp
  • OYgQ.ico
  • %User Profile%\Default Pictures\astronaut.bmp
  • YqIA.ico
  • %User Profile%\Default Pictures\ball.bmp
  • vAYk.ico
  • %User Profile%\Default Pictures\beach.bmp
  • Wykw.ico
  • %User Profile%\Default Pictures\butterfly.bmp
  • COoY.ico
  • %User Profile%\Default Pictures\car.bmp
  • aKIU.ico
  • %User Profile%\Default Pictures\cat.bmp
  • GCMg.ico
  • %User Profile%\Default Pictures\chess.bmp
  • mQcU.ico
  • %User Profile%\Default Pictures\dirt bike.bmp
  • SwUY.ico
  • %User Profile%\Default Pictures\dog.bmp
  • uqYY.ico
  • %User Profile%\Default Pictures\drip.bmp
  • MYQs.ico
  • %User Profile%\Default Pictures\duck.bmp
  • kiYQ.ico
  • %User Profile%\Default Pictures\fish.bmp
  • WyYk.ico
  • %User Profile%\Default Pictures\frog.bmp
  • eEwE.ico
  • %User Profile%\Default Pictures\guitar.bmp
  • AKQo.ico
  • %User Profile%\Default Pictures\horses.bmp
  • esso.ico
  • %User Profile%\Default Pictures\kick.bmp
  • uaEc.ico
  • %User Profile%\Default Pictures\lift-off.bmp
  • MSAM.ico
  • %User Profile%\Default Pictures\palm tree.bmp
  • UMso.ico
  • %User Profile%\Default Pictures\pink flower.bmp
  • YWgs.ico
  • %User Profile%\Default Pictures\red flower.bmp
  • AYYI.ico
  • %User Profile%\Default Pictures\skater.bmp
  • SUMQ.ico
  • %User Profile%\Default Pictures\snowflake.bmp
  • wEMk.ico
  • %User Profile%\User Account Pictures\guest.bmp
  • EaAU.ico
  • %User Profile%\User Account Pictures\Wilbert.bmp
  • yiIw.ico
  • %User Profile%\Sample Music\Beethoven's Symphony No. 9 (Scherzo).wma
  • EckQ.ico
  • %User Profile%\Sample Music\New Stories (Highway Blues).wma
  • WCco.ico
  • %User Profile%\Sample Pictures\Blue hills.jpg
  • cUQQ.ico
  • %User Profile%\Sample Pictures\Sunset.jpg
  • QuIE.ico
  • %User Profile%\Sample Pictures\Water lilies.jpg
  • aYMk.ico
  • %User Profile%\Sample Pictures\Winter.jpg
  • GkAw.ico
  • %Application Data%\Microsoft\Wallpaper1.bmp
  • SQcA.ico

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %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.)

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
EnableLUA = "0"

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
HideFileExt = "1"

(Note: The default value data of the said registry entry is 1.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "2"

(Note: The default value data of the said registry entry is 2.)

Dropping Routine

This file infector drops the following files:

  • %User Profile%\yQcYMwsM\sYQsIcUg.exe
  • %User Profile%\tIYMsMcQ\vEMosMIE.exe
  • %User Profile%\FcUwwsIY\sQEQwUoY.exe
  • %User Profile%\lOQs.txt
  • CUAc.exe
  • SQYQ.exe
  • gQgq.exe
  • ToEi.exe
  • iccc.exe
  • KkgW.exe
  • msMe.exe
  • MoIM.exe
  • eAoy.exe
  • YEYK.exe
  • uIUS.exe
  • ssMW.exe
  • iwgQ.exe
  • ugUS.exe
  • ksEE.exe
  • uAQe.exe
  • oYAG.exe
  • KgcC.exe
  • swsw.exe
  • awgG.exe
  • WAoO.exe
  • cMIY.exe
  • Ckgu.exe
  • OwQO.exe
  • gcgw.exe
  • eYMy.exe
  • GAIc.exe
  • qsUc.exe
  • ycMU.exe
  • uMsS.exe
  • iwQC.exe
  • mAwa.exe
  • eAoq.exe
  • %User Temp%/file.vbs
  • %User Profile%\{AC76BA86-7AD7-1033-7B44-AA0000000001}\setup.exe
  • %User Profile%\Default Pictures\airplane.bmp.exe
  • %User Profile%\Default Pictures\astronaut.bmp.exe
  • %User Profile%\Default Pictures\ball.bmp.exe
  • %User Profile%\Default Pictures\beach.bmp.exe
  • %User Profile%\Default Pictures\butterfly.bmp.exe
  • %User Profile%\Default Pictures\car.bmp.exe
  • %User Profile%\Default Pictures\cat.bmp.exe
  • %User Profile%\Default Pictures\chess.bmp.exe
  • %User Profile%\Default Pictures\dirt bike.bmp.exe
  • %User Profile%\Default Pictures\dog.bmp.exe
  • %User Profile%\Default Pictures\drip.bmp.exe
  • %User Profile%\Default Pictures\duck.bmp.exe
  • %User Profile%\Default Pictures\fish.bmp.exe
  • %User Profile%\Default Pictures\frog.bmp.exe
  • %User Profile%\Default Pictures\guitar.bmp.exe
  • %User Profile%\Default Pictures\horses.bmp.exe
  • %User Profile%\Default Pictures\kick.bmp.exe
  • %User Profile%\Default Pictures\lift-off.bmp.exe
  • %User Profile%\Default Pictures\palm tree.bmp.exe
  • %User Profile%\Default Pictures\pink flower.bmp.exe
  • %User Profile%\Default Pictures\red flower.bmp.exe
  • %User Profile%\Default Pictures\skater.bmp.exe
  • %User Profile%\Default Pictures\snowflake.bmp.exe
  • %User Profile%\User Account Pictures\guest.bmp.exe
  • %User Profile%\User Account Pictures\Wilbert.bmp.exe
  • %User Profile%\Sample Music\Beethoven's Symphony No. 9 (Scherzo).wma.exe
  • %User Profile%\Sample Music\New Stories (Highway Blues).wma.exe
  • %User Profile%\Sample Pictures\Blue hills.jpg.exe
  • %User Profile%\Sample Pictures\Sunset.jpg.exe
  • %User Profile%\Sample Pictures\Water lilies.jpg.exe
  • %User Profile%\Sample Pictures\Winter.jpg.exe
  • %Application Data%\Microsoft\Wallpaper1.bmp.exe

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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.)

Other Details

This file infector deletes itself after execution.

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.750

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

Identify and delete files detected as PE_VIRLOCK.I using either the Startup Disk or Recovery Console

[ Learn More ]

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
    • sYQsIcUg.exe = "%User Profile%\yQcYMwsM\sYQsIcUg.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • vEMosMIE.exe = "%User Profile%\tIYMsMcQ\vEMosMIE.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
    • EnableLUA = "0"

Step 4

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: HideFileExt = "1"
      To: HideFileExt = ""1""
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: Hidden = "2"
      To: Hidden = ""2""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
    • From: Userinit = "%System%\userinit.exe,%User Profile%\tIYMsMcQ\vEMosMIE.exe,"
      To: Userinit = ""%Windows%\system32\userinit.exe,""

Step 5

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 Profile%\yQcYMwsM\sYQsIcUg.exe
  • %User Profile%\tIYMsMcQ\vEMosMIE.exe
  • %User Profile%\FcUwwsIY\sQEQwUoY.exe
  • %User Profile%\lOQs.txt
  • CUAc.exe
  • SQYQ.exe
  • gQgq.exe
  • ToEi.exe
  • iccc.exe
  • KkgW.exe
  • msMe.exe
  • MoIM.exe
  • eAoy.exe
  • YEYK.exe
  • uIUS.exe
  • ssMW.exe
  • iwgQ.exe
  • ugUS.exe
  • ksEE.exe
  • uAQe.exe
  • oYAG.exe
  • KgcC.exe
  • swsw.exe
  • awgG.exe
  • WAoO.exe
  • cMIY.exe
  • Ckgu.exe
  • OwQO.exe
  • gcgw.exe
  • eYMy.exe
  • GAIc.exe
  • qsUc.exe
  • ycMU.exe
  • uMsS.exe
  • iwQC.exe
  • mAwa.exe
  • eAoq.exe
  • %User Temp%/file.vbs
  • %User Profile%\{AC76BA86-7AD7-1033-7B44-AA0000000001}\setup.exe
  • %User Profile%\Default Pictures\airplane.bmp.exe
  • %User Profile%\Default Pictures\astronaut.bmp.exe
  • %User Profile%\Default Pictures\ball.bmp.exe
  • %User Profile%\Default Pictures\beach.bmp.exe
  • %User Profile%\Default Pictures\butterfly.bmp.exe
  • %User Profile%\Default Pictures\car.bmp.exe
  • %User Profile%\Default Pictures\cat.bmp.exe
  • %User Profile%\Default Pictures\chess.bmp.exe
  • %User Profile%\Default Pictures\dirt bike.bmp.exe
  • %User Profile%\Default Pictures\dog.bmp.exe
  • %User Profile%\Default Pictures\drip.bmp.exe
  • %User Profile%\Default Pictures\duck.bmp.exe
  • %User Profile%\Default Pictures\fish.bmp.exe
  • %User Profile%\Default Pictures\frog.bmp.exe
  • %User Profile%\Default Pictures\guitar.bmp.exe
  • %User Profile%\Default Pictures\horses.bmp.exe
  • %User Profile%\Default Pictures\kick.bmp.exe
  • %User Profile%\Default Pictures\lift-off.bmp.exe
  • %User Profile%\Default Pictures\palm tree.bmp.exe
  • %User Profile%\Default Pictures\pink flower.bmp.exe
  • %User Profile%\Default Pictures\red flower.bmp.exe
  • %User Profile%\Default Pictures\skater.bmp.exe
  • %User Profile%\Default Pictures\snowflake.bmp.exe
  • %User Profile%\User Account Pictures\guest.bmp.exe
  • %User Profile%\User Account Pictures\Wilbert.bmp.exe
  • %User Profile%\Sample Music\Beethoven's Symphony No. 9 (Scherzo).wma.exe
  • %User Profile%\Sample Music\New Stories (Highway Blues).wma.exe
  • %User Profile%\Sample Pictures\Blue hills.jpg.exe
  • %User Profile%\Sample Pictures\Sunset.jpg.exe
  • %User Profile%\Sample Pictures\Water lilies.jpg.exe
  • %User Profile%\Sample Pictures\Winter.jpg.exe
  • %Application Data%\Microsoft\Wallpaper1.bmp.exe

Step 6

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.
  • %User Profile%\yQcYMwsM
  • %User Profile%\tIYMsMcQ
  • %User Profile%\FcUwwsIY

Step 7

Scan your computer with your Trend Micro product to clean files detected as PE_VIRLOCK.I. 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.

Step 8

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • aKUE.ico
  • %User Profile%\Default Pictures\airplane.bmp
  • OYgQ.ico
  • %User Profile%\Default Pictures\astronaut.bmp
  • YqIA.ico
  • %User Profile%\Default Pictures\ball.bmp
  • vAYk.ico
  • %User Profile%\Default Pictures\beach.bmp
  • Wykw.ico
  • %User Profile%\Default Pictures\butterfly.bmp
  • COoY.ico
  • %User Profile%\Default Pictures\car.bmp
  • aKIU.ico
  • %User Profile%\Default Pictures\cat.bmp
  • GCMg.ico
  • %User Profile%\Default Pictures\chess.bmp
  • mQcU.ico
  • %User Profile%\Default Pictures\dirt bike.bmp
  • SwUY.ico
  • %User Profile%\Default Pictures\dog.bmp
  • uqYY.ico
  • %User Profile%\Default Pictures\drip.bmp
  • MYQs.ico
  • %User Profile%\Default Pictures\duck.bmp
  • kiYQ.ico
  • %User Profile%\Default Pictures\fish.bmp
  • WyYk.ico
  • %User Profile%\Default Pictures\frog.bmp
  • eEwE.ico
  • %User Profile%\Default Pictures\guitar.bmp
  • AKQo.ico
  • %User Profile%\Default Pictures\horses.bmp
  • esso.ico
  • %User Profile%\Default Pictures\kick.bmp
  • uaEc.ico
  • %User Profile%\Default Pictures\lift-off.bmp
  • MSAM.ico
  • %User Profile%\Default Pictures\palm tree.bmp
  • UMso.ico
  • %User Profile%\Default Pictures\pink flower.bmp
  • YWgs.ico
  • %User Profile%\Default Pictures\red flower.bmp
  • AYYI.ico
  • %User Profile%\Default Pictures\skater.bmp
  • SUMQ.ico
  • %User Profile%\Default Pictures\snowflake.bmp
  • wEMk.ico
  • %User Profile%\User Account Pictures\guest.bmp
  • EaAU.ico
  • %User Profile%\User Account Pictures\Wilbert.bmp
  • yiIw.ico
  • %User Profile%\Sample Music\Beethoven's Symphony No. 9 (Scherzo).wma
  • EckQ.ico
  • %User Profile%\Sample Music\New Stories (Highway Blues).wma
  • WCco.ico
  • %User Profile%\Sample Pictures\Blue hills.jpg
  • cUQQ.ico
  • %User Profile%\Sample Pictures\Sunset.jpg
  • QuIE.ico
  • %User Profile%\Sample Pictures\Water lilies.jpg
  • aYMk.ico
  • %User Profile%\Sample Pictures\Winter.jpg
  • GkAw.ico
  • %Application Data%\Microsoft\Wallpaper1.bmp
  • SQcA.ico


Did this description help? Tell us how we did.