BKDR_SHOTODOR.UQ
Trojan.Blueso!gen (Symantec); Troj/Malit-EX, Mal/MalitRar-B (Sophos); Trojan horse Ransomer.DOR (AVG)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
Threat Type: Backdoor
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This backdoor 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
Arrival Details
This backdoor 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 backdoor creates the following folders:
- \Documents and Settings
- \Documents and Settings\Wilbert
- \Documents and Settings\Wilbert\3c9n37mr
- %User Profile%\10.0\Forms
- %User Profile%\10.0\Collab
- %User Profile%\10.0\Security
- %User Profile%\Security\CRLCache
(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 backdoor adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
3c9n37mr = "\DOCUME~1\Wilbert\3c9n37mr\abtx.vbs"
Other System Modifications
This backdoor deletes the following files:
- %User Startup%\desktop.ini
- %User Profile%\10.0\ReaderMessages-journal
- %Application Data%\Adobe\Acrobat\10.0\SharedDataEvents-journal
(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.. %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 current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)
It adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
HKEY_CURRENT_USER\Software\Adobe\
Adobe Acrobat\10.0
HKEY_CURRENT_USER\Software\Adobe\
Adobe Synchronizer\10.0
HKEY_LOCAL_MACHINE\System\Acrobatbrokerserverdispatchercpp789
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Installer\
Migrated
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Originals
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\AVGeneral
HKEY_CURRENT_USER\Software\Adobe\
Adobe Synchronizer\10.0\Acrobat.com
HKEY_CURRENT_USER\Software\Adobe\
Adobe Synchronizer\10.0\Acrobat.com.v2
HKEY_CURRENT_USER\Software\Adobe\
Adobe Acrobat\10.0\DiskCabs
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Collab
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Collab\
cDocumentCenter
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Collab\
cDocumentCenter\cSettings
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Collab\
cEmailDistribution
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Collab\
cEmailDistribution\cSettings
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Collab\
cInitiationWizardFirstLaunch
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Security
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Security\
cHandlers
HKEY_LOCAL_MACHINE\Software\Adobe\
Acrobat Reader\10.0\AdobeViewer
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
EnableLUA = "0"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = "0"
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Installer\
Migrated
{AC76BA86-7AD7-1033-7B44-AA0000000001} = "1"
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Originals
bDisplayedSplash = "1"
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\AVGeneral
bLastExitNormal = "0"
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Collab\
cDocumentCenter
bAlwaysUseServer = "0"
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Collab\
cDocumentCenter
bAlwaysUseServerFD = "0"
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Collab\
cDocumentCenter
bDefault = "1"
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Collab\
cDocumentCenter
bDefaultFD = "1"
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Collab\
cDocumentCenter
tDistMethod = "UPLOAD"
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Collab\
cDocumentCenter\cSettings
tcSetting = "https://api.{BLOCKED}e.acrobat.com"
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Collab\
cDocumentCenter
tUI = "Acrobat.com (Recommended)"
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Collab\
cDocumentCenter
tURL = "urn://ns.{BLOCKED}e.com/Collaboration/SharedReview/Acrobat.com"
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Collab\
cEmailDistribution
bAlwaysUseServerFD = "0"
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Collab\
cEmailDistribution
bDefaultFD = "0"
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Collab\
cEmailDistribution
tDistMethod = "EMAIL"
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Collab\
cEmailDistribution
tUI = "Manually collect responses in my email inbox"
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Collab\
cEmailDistribution
tURL = "urn://ns.{BLOCKED}e.com/Collaboration/Forms/Email"
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Collab\
cInitiationWizardFirstLaunch
bIsFirstLaunchER = "1"
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Collab\
cInitiationWizardFirstLaunch
bIsFirstLaunchFD = "1"
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Collab\
cInitiationWizardFirstLaunch
bIsFirstLaunchSF = "1"
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Collab\
cInitiationWizardFirstLaunch
bIsFirstLaunchSR = "1"
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Collab\
cInitiationWizardFirstLaunch
bIsFirstLaunchUF = "1"
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Security\
cHandlers
aPrivKey = "Adobe.PPKLite"
HKEY_LOCAL_MACHINE\SOFTWARE\Adobe\
Acrobat Reader\10.0\AdobeViewer
EULA = "1"
HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\AdobeViewer
EULA = "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"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoFolderOptions = "1"
It deletes the following registry keys:
HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run\
OptionalComponents\IMAIL
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run\
OptionalComponents\MAPI
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run\
OptionalComponents\MSFS
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run\
OptionalComponents
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Dropping Routine
This backdoor drops the following files:
- __tmp_rar_sfx_access_check_66953
- xotsouerhvvg.LEG
- ebjpxjdbwm.exe
- shxwnp.UGF
- jhlhglofomb.HIS
- Payment_Advice(2).pdf
- %User Startup%\start.lnk
- %Application Data%\Adobe\Color\ACECache11.lst
- %Application Data%\Adobe\Acrobat\10.0\UserCache.bin
- %User Temp%\Temporary Internet Files
- %User Temp%\Temporary Internet Files\Content.IE5
- %User Temp%\Temporary Internet Files\Content.IE5\EL8ZRUR8
- %User Temp%\Temporary Internet Files\Content.IE5\C3GXUF8B
- %User Temp%\Temporary Internet Files\Content.IE5\TMHP3LT9
- %User Temp%\Temporary Internet Files\Content.IE5\R6MEDUE0
- %User Temp%\Cookies
- %User Temp%\History
- %User Temp%\History\History.IE5
- %User Profile%\10.0\rdrmessage.zip
- %User Profile%\10.0\Forms
- %User Profile%\10.0\Collab
- %User Profile%\10.0\Security
- %User Profile%\Security\CRLCache
- %Windows%\Microsoft.NET\Framework\v2.0.50727\.Identifier
(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.. %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.. %Windows% is the Windows folder, which is usually C:\Windows.)
Other Details
This backdoor connects to the following possibly malicious URL:
- http://acroipm.{BLOCKED}e.com/10/rdr/ENU/win/nooem/none/message.zip
- {BLOCKED}0.1
- {BLOCKED}21.19
- {BLOCKED}.170.134
This report is generated via an automated analysis system.
SOLUTION
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
Restart in Safe Mode
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies
- System
- In HKEY_CURRENT_USER\Software\Adobe\Adobe Acrobat
- 10.0
- In HKEY_CURRENT_USER\Software\Adobe\Adobe Synchronizer
- 10.0
- In HKEY_LOCAL_MACHINE\System
- Acrobatbrokerserverdispatchercpp789
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Installer
- Migrated
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0
- Originals
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0
- AVGeneral
- In HKEY_CURRENT_USER\Software\Adobe\Adobe Synchronizer\10.0
- Acrobat.com
- In HKEY_CURRENT_USER\Software\Adobe\Adobe Synchronizer\10.0
- Acrobat.com.v2
- In HKEY_CURRENT_USER\Software\Adobe\Adobe Acrobat\10.0
- DiskCabs
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0
- Collab
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Collab
- cDocumentCenter
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Collab\cDocumentCenter
- cSettings
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Collab
- cEmailDistribution
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Collab\cEmailDistribution
- cSettings
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Collab
- cInitiationWizardFirstLaunch
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0
- Security
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Security
- cHandlers
- In HKEY_LOCAL_MACHINE\Software\Adobe\Acrobat Reader\10.0
- AdobeViewer
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\RunOnce
- 3c9n37mr = "\DOCUME~1\Wilbert\3c9n37mr\abtx.vbs"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
- EnableLUA = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- ShowSuperHidden = "0"
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Installer\Migrated
- {AC76BA86-7AD7-1033-7B44-AA0000000001} = "1"
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Originals
- bDisplayedSplash = "1"
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\AVGeneral
- bLastExitNormal = "0"
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Collab\cDocumentCenter
- bAlwaysUseServer = "0"
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Collab\cDocumentCenter
- bAlwaysUseServerFD = "0"
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Collab\cDocumentCenter
- bDefault = "1"
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Collab\cDocumentCenter
- bDefaultFD = "1"
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Collab\cDocumentCenter
- tDistMethod = "UPLOAD"
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Collab\cDocumentCenter\cSettings
- tcSetting = "https://api.{BLOCKED}e.acrobat.com"
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Collab\cDocumentCenter
- tUI = "Acrobat.com (Recommended)"
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Collab\cDocumentCenter
- tURL = "urn://ns.{BLOCKED}e.com/Collaboration/SharedReview/Acrobat.com"
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Collab\cEmailDistribution
- bAlwaysUseServerFD = "0"
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Collab\cEmailDistribution
- bDefaultFD = "0"
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Collab\cEmailDistribution
- tDistMethod = "EMAIL"
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Collab\cEmailDistribution
- tUI = "Manually collect responses in my email inbox"
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Collab\cEmailDistribution
- tURL = "urn://ns.{BLOCKED}e.com/Collaboration/Forms/Email"
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Collab\cInitiationWizardFirstLaunch
- bIsFirstLaunchER = "1"
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Collab\cInitiationWizardFirstLaunch
- bIsFirstLaunchFD = "1"
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Collab\cInitiationWizardFirstLaunch
- bIsFirstLaunchSF = "1"
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Collab\cInitiationWizardFirstLaunch
- bIsFirstLaunchSR = "1"
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Collab\cInitiationWizardFirstLaunch
- bIsFirstLaunchUF = "1"
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Security\cHandlers
- aPrivKey = "Adobe.PPKLite"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Adobe\Acrobat Reader\10.0\AdobeViewer
- EULA = "1"
- In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\AdobeViewer
- EULA = "1"
Step 6
Search and delete these components
- __tmp_rar_sfx_access_check_66953
- xotsouerhvvg.LEG
- ebjpxjdbwm.exe
- shxwnp.UGF
- jhlhglofomb.HIS
- Payment_Advice(2).pdf
- %User Startup%\start.lnk
- %Application Data%\Adobe\Color\ACECache11.lst
- %Application Data%\Adobe\Acrobat\10.0\UserCache.bin
- %User Temp%\Temporary Internet Files
- %User Temp%\Temporary Internet Files\Content.IE5
- %User Temp%\Temporary Internet Files\Content.IE5\EL8ZRUR8
- %User Temp%\Temporary Internet Files\Content.IE5\C3GXUF8B
- %User Temp%\Temporary Internet Files\Content.IE5\TMHP3LT9
- %User Temp%\Temporary Internet Files\Content.IE5\R6MEDUE0
- %User Temp%\Cookies
- %User Temp%\History
- %User Temp%\History\History.IE5
- %User Profile%\10.0\rdrmessage.zip
- %User Profile%\10.0\Forms
- %User Profile%\10.0\Collab
- %User Profile%\10.0\Security
- %User Profile%\Security\CRLCache
- %Windows%\Microsoft.NET\Framework\v2.0.50727\.Identifier
Step 7
Search and delete these folders
- \Documents and Settings
- \Documents and Settings\Wilbert
- \Documents and Settings\Wilbert\3c9n37mr
- %User Profile%\10.0\Forms
- %User Profile%\10.0\Collab
- %User Profile%\10.0\Security
- %User Profile%\Security\CRLCache
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_SHOTODOR.UQ. 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 9
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.
- %User Startup%\desktop.ini
- %User Profile%\10.0\ReaderMessages-journal
- %Application Data%\Adobe\Acrobat\10.0\SharedDataEvents-journal
Step 10
Restore these deleted registry keys/values from backup
*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.
- In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion
- Run
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\OptionalComponents
- IMAIL
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\OptionalComponents
- MAPI
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\OptionalComponents
- MSFS
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- OptionalComponents
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion
- Run
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