TROJ_DIRCRYPT.K
Ransom:Win32/Dircrypt.A (Microsoft); [0003bf14.EXE]:Generic.dx!1D27A7210F54 (McAfee); Trojan.Dropper (Symantec); Trojan-Ransom.Win32.Blocker.bqlz (Kaspersky); Troj/Ransom-AAN (Sophos); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse Ransomer.BZC, Trojan horse Ransomer.BZC.dropper (AVG)
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted:
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 disables Task Manager, Registry Editor, and Folder Options.
TECHNICAL DETAILS
24,576 bytes
EXE
Yes
07 Aug 2015
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:
- %Program Files%\MSN Gaming Zone\otbQbYeC.exe
- %Application Data%\Microsoft\aJTdzIeE.exe
- %User Temp%\nJaMdEHM.exe
(Note: %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.. %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.. %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.)
It creates the following folders:
- %User Profile%\Application Data\Dirty
- %Application Data%\kzpIsLLy
- %Program Files%\Dirty
- %Application Data%\Dirty
- %Application Data%\cssCKgnt
- %Application Data%\kzpIsLLy\css
- %Application Data%\kzpIsLLy\images
- %Application Data%\kzpIsLLy\images/content
(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.. %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
ZiHyZnrI = "%Application Data%\Microsoft\aJTdzIeE.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,,%Program Files%\MSN Gaming Zone\otbQbYeC.exe"
(Note: The default value data of the said registry entry is %Windows%\system32\userinit.exe,.)
Other System Modifications
This Trojan deletes the following files:
- %Program Files%\MSN Gaming Zone\otbQbYeC.exe:Zone.Identifier
- %Application Data%\Microsoft\aJTdzIeE.exe:Zone.Identifier
- %User Startup%\RbKsrITa.exe:Zone.Identifier
- %User Temp%\nJaMdEHM.exe:Zone.Identifier
- %User Profile%\S-1-5-21-1645522239-1292428093-682003330-1003\4a4ad625f364c18c1ab6565a40b9a3ba_6abce574-4afc-42c5-8ab9-5739a84d8a8b
(Note: %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.. %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.. %User Startup% is the current user's Startup folder, which is usually C:\Documents and Settings\{user}\Start Menu\Programs\Startup on Windows 2000 and XP, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows Vista, 7, and 8.. %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.. %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.)
It deletes the following folders:
- %System Root%\{A14913F0-13E4-848E-F528-66C3B4FB4FC0}
(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)
It adds the following registry keys:
HKEY_LOCAL_MACHINE\Software\{EDDF73F5-5E7A-CF14-30BF-A14913F07575}
HKEY_CURRENT_USER\Software\{EDDF73F5-5E7A-CF14-30BF-A14913F07575}
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\policies\
system
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\{EDDF73F5-5E7A-CF14-30BF-A14913F07575}
ID = "{random values}"
HKEY_CURRENT_USER\Software\{EDDF73F5-5E7A-CF14-30BF-A14913F07575}
ID = "{random values}"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
EnableLUA = "0"
HKEY_CURRENT_USER\Software\{EDDF73F5-5E7A-CF14-30BF-A14913F07575}
PeriodDisabed = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\{EDDF73F5-5E7A-CF14-30BF-A14913F07575}
PeriodDisabed = "1"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
DisableNotifications = "1"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
DoNotAllowExceptions = "0"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
EnableFirewall = "0"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
UacDisableNotify = "1"
HKEY_CURRENT_USER\Software\{EDDF73F5-5E7A-CF14-30BF-A14913F07575}
Personal = "64.212.34.30_Level 3 Communications__"
HKEY_LOCAL_MACHINE\SOFTWARE\{EDDF73F5-5E7A-CF14-30BF-A14913F07575}
Personal = "64.212.34.30_Level 3 Communications__"
HKEY_CURRENT_USER\Software\{EDDF73F5-5E7A-CF14-30BF-A14913F07575}
LID = "13ad76c8"
HKEY_LOCAL_MACHINE\SOFTWARE\{EDDF73F5-5E7A-CF14-30BF-A14913F07575}
LID = "13ad76c8"
HKEY_CURRENT_USER\Software\{EDDF73F5-5E7A-CF14-30BF-A14913F07575}
Landing = "%Application Data%\kzpIsLLy"
HKEY_LOCAL_MACHINE\SOFTWARE\{EDDF73F5-5E7A-CF14-30BF-A14913F07575}
Landing = "%Application Data%\kzpIsLLy"
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\wscsvc
Start = "4"
(Note: The default value data of the said registry entry is 2.)
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\wuauserv
Start = "4"
(Note: The default value data of the said registry entry is 2.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
AntiVirusOverride = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
AntiVirusDisableNotify = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
FirewallDisableNotify = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
FirewallOverride = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
UpdatesDisableNotify = "1"
It creates the following registry entry(ies) to disable Task Manager, Registry Tools and Folder Options:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
system
DisableTaskMgr = "1"
Dropping Routine
This Trojan drops the following files:
- %User Profile%\Dirty\alertwall.jpg
- %Program Files%\Dirty\DirtyDecrypt.exe
- %User Profile%\Dirty\DirtyDecrypt.exe
- %Application Data%\Dirty\DirtyDecrypt.exe
- %Application Data%\kzpIsLLy\css/all.css
- %Application Data%\kzpIsLLy\css/style-custom.css
- %Application Data%\kzpIsLLy\images/arrow.png
- %Application Data%\kzpIsLLy\images/bg-box-bottom.png
- %Application Data%\kzpIsLLy\images/bg-box.jpg
- %Application Data%\kzpIsLLy\images/bg-btn-sprite.png
- %Application Data%\kzpIsLLy\images/bg-header-repeat.gif
- %Application Data%\kzpIsLLy\images/bg-html.jpg
- %Application Data%\kzpIsLLy\images/bg-li.png
- %Application Data%\kzpIsLLy\images/bg-track.gif
- %Application Data%\kzpIsLLy\images/content/img1.jpg
- %Application Data%\kzpIsLLy\images/content/img2.jpg
- %Application Data%\kzpIsLLy\images/content/img3.jpg
- %Application Data%\kzpIsLLy\images/content/img4.jpg
- %Application Data%\kzpIsLLy\images/dominicks.png
- %Application Data%\kzpIsLLy\images/dotted-copy.png
- %Application Data%\kzpIsLLy\images/dotted-small.png
- %Application Data%\kzpIsLLy\images/dotted.png
- %Application Data%\kzpIsLLy\images/epay.png
- %Application Data%\kzpIsLLy\images/genuardis.png
- %Application Data%\kzpIsLLy\images/logo-ie.png
- %Application Data%\kzpIsLLy\images/logo.png
- %Application Data%\kzpIsLLy\images/moneypack.png
- %Application Data%\kzpIsLLy\images/nowprepay.png
- %Application Data%\kzpIsLLy\images/oder.png
- %Application Data%\kzpIsLLy\images/paysafe.png
- %Application Data%\kzpIsLLy\images/pioneer.png
- %Application Data%\kzpIsLLy\images/precash.png
- %Application Data%\kzpIsLLy\images/price.png
- %Application Data%\kzpIsLLy\images/safeway.png
- %Application Data%\kzpIsLLy\images/sagamie.png
- %Application Data%\kzpIsLLy\images/shoprite.png
- %Application Data%\kzpIsLLy\images/total.png
- %Application Data%\kzpIsLLy\images/usa.png
- %Application Data%\kzpIsLLy\images/webcam.png
- %Application Data%\kzpIsLLy\images/x.jpg
- %Application Data%\kzpIsLLy\index.html
- %User Startup%\RbKsrITa.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.. %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.. %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.. %User Startup% is the current user's Startup folder, which is usually C:\Documents and Settings\{user}\Start Menu\Programs\Startup on Windows 2000 and XP, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)
Other Details
This Trojan connects to the following possibly malicious URL:
- {BLOCKED}.162.67
- {BLOCKED}0.1
This report is generated via an automated analysis system.
SOLUTION
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 TROJ_DIRCRYPT.K using either the Startup Disk or Recovery Console
Step 3
Enable Registry Editor, Task Manager, and Folder options
Step 4
Delete this registry key
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_LOCAL_MACHINE\Software
- {EDDF73F5-5E7A-CF14-30BF-A14913F07575}
- In HKEY_CURRENT_USER\Software
- {EDDF73F5-5E7A-CF14-30BF-A14913F07575}
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\policies
- system
Step 5
Delete this registry value
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
- ZiHyZnrI = "%Application Data%\Microsoft\aJTdzIeE.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\{EDDF73F5-5E7A-CF14-30BF-A14913F07575}
- ID = "{random values}"
- In HKEY_CURRENT_USER\Software\{EDDF73F5-5E7A-CF14-30BF-A14913F07575}
- ID = "{random values}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
- EnableLUA = "0"
- In HKEY_CURRENT_USER\Software\{EDDF73F5-5E7A-CF14-30BF-A14913F07575}
- PeriodDisabed = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\{EDDF73F5-5E7A-CF14-30BF-A14913F07575}
- PeriodDisabed = "1"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
- DisableNotifications = "1"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
- DoNotAllowExceptions = "0"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
- EnableFirewall = "0"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
- UacDisableNotify = "1"
- In HKEY_CURRENT_USER\Software\{EDDF73F5-5E7A-CF14-30BF-A14913F07575}
- Personal = "64.212.34.30_Level 3 Communications__"
- In HKEY_LOCAL_MACHINE\SOFTWARE\{EDDF73F5-5E7A-CF14-30BF-A14913F07575}
- Personal = "64.212.34.30_Level 3 Communications__"
- In HKEY_CURRENT_USER\Software\{EDDF73F5-5E7A-CF14-30BF-A14913F07575}
- LID = "13ad76c8"
- In HKEY_LOCAL_MACHINE\SOFTWARE\{EDDF73F5-5E7A-CF14-30BF-A14913F07575}
- LID = "13ad76c8"
- In HKEY_CURRENT_USER\Software\{EDDF73F5-5E7A-CF14-30BF-A14913F07575}
- Landing = "%Application Data%\kzpIsLLy"
- In HKEY_LOCAL_MACHINE\SOFTWARE\{EDDF73F5-5E7A-CF14-30BF-A14913F07575}
- Landing = "%Application Data%\kzpIsLLy"
Step 6
Restore these modified registry values
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_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\wscsvc
- From: Start = "4"
To: Start = ""2""
- From: Start = "4"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\wuauserv
- From: Start = "4"
To: Start = ""2""
- From: Start = "4"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
- AntiVirusOverride = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
- AntiVirusDisableNotify = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
- FirewallDisableNotify = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
- FirewallOverride = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
- UpdatesDisableNotify = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
- From: Userinit = "%System%\userinit.exe,,%Program Files%\MSN Gaming Zone\otbQbYeC.exe"
To: Userinit = ""%Windows%\system32\userinit.exe,""
- From: Userinit = "%System%\userinit.exe,,%Program Files%\MSN Gaming Zone\otbQbYeC.exe"
Step 7
Search and delete these components
- %User Profile%\Dirty\alertwall.jpg
- %Program Files%\Dirty\DirtyDecrypt.exe
- %User Profile%\Dirty\DirtyDecrypt.exe
- %Application Data%\Dirty\DirtyDecrypt.exe
- %Application Data%\kzpIsLLy\css/all.css
- %Application Data%\kzpIsLLy\css/style-custom.css
- %Application Data%\kzpIsLLy\images/arrow.png
- %Application Data%\kzpIsLLy\images/bg-box-bottom.png
- %Application Data%\kzpIsLLy\images/bg-box.jpg
- %Application Data%\kzpIsLLy\images/bg-btn-sprite.png
- %Application Data%\kzpIsLLy\images/bg-header-repeat.gif
- %Application Data%\kzpIsLLy\images/bg-html.jpg
- %Application Data%\kzpIsLLy\images/bg-li.png
- %Application Data%\kzpIsLLy\images/bg-track.gif
- %Application Data%\kzpIsLLy\images/content/img1.jpg
- %Application Data%\kzpIsLLy\images/content/img2.jpg
- %Application Data%\kzpIsLLy\images/content/img3.jpg
- %Application Data%\kzpIsLLy\images/content/img4.jpg
- %Application Data%\kzpIsLLy\images/dominicks.png
- %Application Data%\kzpIsLLy\images/dotted-copy.png
- %Application Data%\kzpIsLLy\images/dotted-small.png
- %Application Data%\kzpIsLLy\images/dotted.png
- %Application Data%\kzpIsLLy\images/epay.png
- %Application Data%\kzpIsLLy\images/genuardis.png
- %Application Data%\kzpIsLLy\images/logo-ie.png
- %Application Data%\kzpIsLLy\images/logo.png
- %Application Data%\kzpIsLLy\images/moneypack.png
- %Application Data%\kzpIsLLy\images/nowprepay.png
- %Application Data%\kzpIsLLy\images/oder.png
- %Application Data%\kzpIsLLy\images/paysafe.png
- %Application Data%\kzpIsLLy\images/pioneer.png
- %Application Data%\kzpIsLLy\images/precash.png
- %Application Data%\kzpIsLLy\images/price.png
- %Application Data%\kzpIsLLy\images/safeway.png
- %Application Data%\kzpIsLLy\images/sagamie.png
- %Application Data%\kzpIsLLy\images/shoprite.png
- %Application Data%\kzpIsLLy\images/total.png
- %Application Data%\kzpIsLLy\images/usa.png
- %Application Data%\kzpIsLLy\images/webcam.png
- %Application Data%\kzpIsLLy\images/x.jpg
- %Application Data%\kzpIsLLy\index.html
- %User Startup%\RbKsrITa.exe
Step 8
Search and delete these folders
- %User Profile%\Application Data\Dirty
- %Application Data%\kzpIsLLy
- %Program Files%\Dirty
- %Application Data%\Dirty
- %Application Data%\cssCKgnt
- %Application Data%\kzpIsLLy\css
- %Application Data%\kzpIsLLy\images
- %Application Data%\kzpIsLLy\images/content
Step 9
Scan your computer with your Trend Micro product to delete files detected as TROJ_DIRCRYPT.K. 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 10
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.
- %Program Files%\MSN Gaming Zone\otbQbYeC.exe:Zone.Identifier
- %Application Data%\Microsoft\aJTdzIeE.exe:Zone.Identifier
- %User Startup%\RbKsrITa.exe:Zone.Identifier
- %User Temp%\nJaMdEHM.exe:Zone.Identifier
- %User Profile%\S-1-5-21-1645522239-1292428093-682003330-1003\4a4ad625f364c18c1ab6565a40b9a3ba_6abce574-4afc-42c5-8ab9-5739a84d8a8b
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