BKDR_BIFROSE.BKD
Backdoor:Win32/Bifrose (Microsoft); Mal/Whybo-A (Sophos)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Backdoor
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
Dropped by other malware, Downloaded from the Internet
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 does not have any propagation routine.
It executes commands from a remote malicious user, effectively compromising the affected system. It connects to a website to send and receive information.
It does not have any downloading capability.
It deletes the initially executed copy of itself.
TECHNICAL DETAILS
107,912 bytes
EXE
Yes
27 May 2011
Connects to URLs/IPs, Compromises system security, Drops files
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:
- %Program Files%\Internet Explorer\IeCheck.exe
(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)
It stays resident in memory by creating the following process(es):
- svchost.exe
Autostart Technique
This backdoor adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{e3df6b419d1f}
Stubpath = "%Program Files%\Internet Explorer\IeCheck"
Other System Modifications
This backdoor adds the following registry entries:
HKEY_CURRENT_USER\Software\Google
ActiveSettings = "{hex value}"
It adds the following registry keys as part of its installation routine:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{e3df6b419d1f}
Propagation
This backdoor does not have any propagation routine.
Backdoor Routine
This backdoor executes the following commands from a remote malicious user:
- Close opened files
- Create a directory
- Delete a directory (including its contents)
- Delete a file
- Get drive type of all drives
- List contents of the malware's current directory
- Load a .DLL file or open a file
- Move a file
- Open a file
- Open a remote command prompt
- Read from the opened file
- Retrieve email info from the following:
- Outlook IMAP and POP3
- Outlook 2002 IMAP and POP3
- Outlook 2003 IMAP and POP3
- Start a process
- Write to the opened file
It connects to the following websites to send and receive information:
- {BLOCKED}v.{BLOCKED}s.us
Download Routine
This backdoor does not have any downloading capability.
Other Details
This backdoor deletes the initially executed copy of itself
NOTES:
It does not have rootkit capabilities.
It does not exploit any vulnerability.
SOLUTION
8.900
8.184.07
27 May 2011
8.185.00
27 May 2011
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
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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components
- {e3df6b419d1f}
- {e3df6b419d1f}
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_CURRENT_USER\Software\Google
- ActiveSettings = "{hex value}"
- ActiveSettings = "{hex value}"
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_BIFROSE.BKD. 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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