WORM_AUTORUN.AEN
Backdoor:Win32/Popwin.B (Microsoft); Generic Malware.bc (McAfee); Backdoor.Trojan (Symantec); Worm.Win32.AutoRun.bsch (Kaspersky); Backdoor.Win32.Popwin.B (v) (Sunbelt)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This worm 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
20,480 bytes
EXE
No
13 Oct 2012
Arrival Details
This worm 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 worm creates the following folders:
- %User Profile%\Application Data\VMware
(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)
Other System Modifications
This worm adds the following registry keys:
HKEY_CURRENT_USER\SYSTEM\CurrentControlSet\
Services\EBCF5B90
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\EBCF5B90
Description = "C74F4050"
HKEY_CURRENT_USER\SYSTEM\CurrentControlSet\
Services\EBCF5B90
Description = "C74F4050"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\EBCF5B90
DisplayName = "EBCF5B90"
HKEY_CURRENT_USER\SYSTEM\CurrentControlSet\
Services\EBCF5B90
DisplayName = "EBCF5B90"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\EBCF5B90
ErrorControl = "1"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\EBCF5B90
ImagePath = "%System%\9788BBD0.EXE -k"
HKEY_CURRENT_USER\SYSTEM\CurrentControlSet\
Services\EBCF5B90
ImagePath = "%System%\9788BBD0.EXE -k"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\EBCF5B90
ObjectName = "LocalSystem"
HKEY_CURRENT_USER\SYSTEM\CurrentControlSet\
Services\EBCF5B90
ObjectName = "LocalSystem"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\EBCF5B90
Start = "2"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\EBCF5B90
Type = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT
ReportBootOk = "1"
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
PCHealth\ErrorReporting
DoReport = "0"
(Note: The default value data of the said registry entry is 1.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
PCHealth\ErrorReporting
ShowUI = "0"
(Note: The default value data of the said registry entry is 1.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\Hidden\
SHOWALL
CheckedValue = "0"
(Note: The default value data of the said registry entry is 1.)
It deletes the following registry keys:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\ERSvc\Parameters
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\ERSvc\Security
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\ERSvc\Enum
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\ERSvc
Dropping Routine
This worm drops the following files:
- %System%\del.bat
- %System%\C74F4050.DLL
- %System Root%\auto.exe
- d:\auto.exe
- e:\auto.exe
- f:\auto.exe
- g:\auto.exe
- h:\auto.exe
- i:\auto.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
Other Details
This worm connects to the following possibly malicious URL:
It deletes itself after execution.
This report is generated via an automated analysis system.
SOLUTION
9.200
Step 1
For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
Step 2
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\SYSTEM\CurrentControlSet\Services
- EBCF5B90
Step 3
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\SYSTEM\ControlSet001\Services\EBCF5B90
- Description = "C74F4050"
- In HKEY_CURRENT_USER\SYSTEM\CurrentControlSet\Services\EBCF5B90
- Description = "C74F4050"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\EBCF5B90
- DisplayName = "EBCF5B90"
- In HKEY_CURRENT_USER\SYSTEM\CurrentControlSet\Services\EBCF5B90
- DisplayName = "EBCF5B90"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\EBCF5B90
- ErrorControl = "1"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\EBCF5B90
- ImagePath = "%System%\9788BBD0.EXE -k"
- In HKEY_CURRENT_USER\SYSTEM\CurrentControlSet\Services\EBCF5B90
- ImagePath = "%System%\9788BBD0.EXE -k"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\EBCF5B90
- ObjectName = "LocalSystem"
- In HKEY_CURRENT_USER\SYSTEM\CurrentControlSet\Services\EBCF5B90
- ObjectName = "LocalSystem"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\EBCF5B90
- Start = "2"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\EBCF5B90
- Type = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT
- ReportBootOk = "1"
Step 4
Restore this modified 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\PCHealth\ErrorReporting
- From: DoReport = "0"
To: DoReport = ""1""
- From: DoReport = "0"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\PCHealth\ErrorReporting
- From: ShowUI = "0"
To: ShowUI = ""1""
- From: ShowUI = "0"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL
- From: CheckedValue = "0"
To: CheckedValue = ""1""
- From: CheckedValue = "0"
Step 5
Search and delete these files
- %System%\del.bat
- %System%\C74F4050.DLL
- %System Root%\auto.exe
- d:\auto.exe
- e:\auto.exe
- f:\auto.exe
- g:\auto.exe
- h:\auto.exe
- i:\auto.exe
Step 6
Search and delete this folder
- %User Profile%\Application Data\VMware
Step 7
Scan your computer with your Trend Micro product to delete files detected as WORM_AUTORUN.AEN. 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 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_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\ERSvc
- Parameters
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\ERSvc
- Security
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\ERSvc
- Enum
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
- ERSvc
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