BKDR_BLACKHOLE.E
Backdoor:Win32/Blackhole.J (Microsoft); BackDoor-CGX.svr (McAfee); Backdoor.Singu (Symantec); Backdoor.Win32.BlackHole.qye (Kaspersky); BehavesLike.Win32.Malware.wsc (mx-v) (Sunbelt); Trojan horse BackDoor.Generic2.ZXA (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
206,278 bytes
EXE
No
10 May 2013
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 drops the following copies of itself into the affected system:
- %Windows%\ssytem.exe
(Note: %Windows% is the Windows folder, which is usually C:\Windows.)
Other System Modifications
This backdoor adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
WinOldApp
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
EnableAutodial = "{random values}"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
EnableAutodisconnect = "{random values}"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings
EnableAutodial = "{random values}"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings
EnableAutodisconnect = "{random values}"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Hardware Profiles\0001\Software\
Microsoft\windows\CurrentVersion\
Internet Settings
EnableAutodial = "{random values}"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Hardware Profiles\0001\Software\
Microsoft\windows\CurrentVersion\
Internet Settings
EnableAutodisconnect = "{random values}"
It modifies the following registry entries:
HKEY_CURRENT_USER\Control Panel\International
sDate = "-"
(Note: The default value data of the said registry entry is /.)
Dropping Routine
This backdoor drops the following files:
- %System Root%\$$a$$.bat
- %Windows%\ssytem.cfg
- %System%\KeySpy.dll
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %Windows% is the Windows folder, which is usually C:\Windows.. %System% is the Windows system folder, which is usually C:\Windows\System32.)
Other Details
This backdoor deletes itself after execution.
This report is generated via an automated analysis system.
SOLUTION
9.300
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
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
- WinOldApp
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
- EnableAutodial = "{random values}"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
- EnableAutodisconnect = "{random values}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings
- EnableAutodial = "{random values}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings
- EnableAutodisconnect = "{random values}"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Hardware Profiles\0001\Software\Microsoft\windows\CurrentVersion\Internet Settings
- EnableAutodial = "{random values}"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Hardware Profiles\0001\Software\Microsoft\windows\CurrentVersion\Internet Settings
- EnableAutodisconnect = "{random values}"
Step 4
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_CURRENT_USER\Control Panel\International
- From: sDate = "-"
To: sDate = ""/""
- From: sDate = "-"
Step 5
Search and delete these components
- %System Root%\a.bat
- %Windows%\ssytem.cfg
- %System%\KeySpy.dll
• For Windows Vista and Windows 7 users:
- Click Start>Computer.
- In the Search input box, type:
- %System Root%\a.bat
- %Windows%\ssytem.cfg
- %System%\KeySpy.dll
- Once located, select the file then press SHIFT+DELETE to delete it.
- Repeat the said steps for all files listed.
*Note: Read the following Microsoft page if these steps do not work on Windows 7.
Step 6
Scan your computer with your Trend Micro product to delete files detected as BKDR_BLACKHOLE.E. 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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