BKDR_MOSUCKER.B
Backdoor:Win32/Mosucker.B (Microsoft); BackDoor-EE.gen (McAfee); Backdoor.Mosuck (Symantec); Backdoor.Win32.MoSucker.b (Kaspersky); ERROR (Sunbelt); Trojan horse BackDoor.Mosucker.CY (AVG)
Windows 2000, Windows XP, Windows Server 2003
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 deletes itself after execution.
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.
Autostart Technique
This backdoor adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
minimo = "{malware path and file name}"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunOnce
minimo = "{malware path and file name}"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunOnceEx
minimo = "{malware path and file name}"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
minimo = "%Windows%\Fonts\lsass.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunOnce
minimo = "%Windows%\Fonts\lsass.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunOnceEx
minimo = "%Windows%\Fonts\lsass.exe"
Other System Modifications
This backdoor adds the following registry keys:
HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
Options\Windows XP
HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
YJVQFPM27367210000XUEMYGKG\YJVQFPM27367210000XUEMYGKG
It adds the following registry entries:
HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
Options\Windows XP
1 = "???©°ªy{@}{@}"
HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
YJVQFPM27367210000XUEMYGKG\YJVQFPM27367210000XUEMYGKG
# = "¢???v??¬Î²¼¨¾Îƾ¿Å½Á »Ê´?Ë~¼Á³"
HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
YJVQFPM27367210000XUEMYGKG\YJVQFPM27367210000XUEMYGKG
1 = "¡¤?¡°vV??x?t??sQ????yw£m"
HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
YJVQFPM27367210000XUEMYGKG\YJVQFPM27367210000XUEMYGKG
2 = "?????v??¬?????e????{??X????{???S??{???Q?"
HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
Options\Windows XP
1 = "??¨{@}{@}"
Dropping Routine
This backdoor drops the following files:
- %System Root%\evel.bat
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
Other Details
This backdoor deletes itself after execution.
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
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\VB and VBA Program Settings\Options
- Windows XP
- In HKEY_CURRENT_USER\Software\VB and VBA Program Settings
- YJVQFPM27367210000XUEMYGKG
Step 4
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- minimo = "{malware path and file name}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce
- minimo = "{malware path and file name}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnceEx
- minimo = "{malware path and file name}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- minimo = "%Windows%\Fonts\lsass.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce
- minimo = "%Windows%\Fonts\lsass.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnceEx
- minimo = "%Windows%\Fonts\lsass.exe"
- In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\Options\Windows XP
- 1 = "???©°ªy{@}{@}"
- In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\YJVQFPM27367210000XUEMYGKG\YJVQFPM27367210000XUEMYGKG
- # = "¢???v??¬Î²¼¨¾Îƾ¿Å½Á »Ê´?Ë~¼Á³"
- In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\YJVQFPM27367210000XUEMYGKG\YJVQFPM27367210000XUEMYGKG
- 1 = "¡¤?¡°vV??x?t??sQ????yw£m"
- In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\YJVQFPM27367210000XUEMYGKG\YJVQFPM27367210000XUEMYGKG
- 2 = "?????v??¬?????e????{??X????{???S??{???Q?"
- In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\Options\Windows XP
- 1 = "??¨{@}{@}"
Step 5
Search and delete this file
- %System Root%\evel.bat
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_MOSUCKER.B. 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.
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