BKDR_BIFROSE.BG
TrojanDropper:Win32/Small.CE (Microsoft); MultiDropper-CE (McAfee); Trojan Horse (Symantec); Trojan-Dropper.Win32.Joiner.bk (Kaspersky); BehavesLike.Win32.Malware.wsc (mx-v) (Sunbelt); ERROR (FSecure)
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.
TECHNICAL DETAILS
69,152 bytes
EXE
Yes
28 Dec 2012
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_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
putil = "%Windows%\~2.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
msreg.exe = "%Windows%\msreg.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Memory Check = "%Windows%\MemChk.exe"
Other System Modifications
This backdoor deletes the following files:
- %Temp%\temp.dll
(Note: %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp.)
It adds the following registry keys:
HKEY_CURRENT_USER\SOFTWARE\Mirabilis\
ICQ\NewOwners
HKEY_LOCAL_MACHINE\SOFTWARE\Miranda
HKEY_LOCAL_MACHINE\SOFTWARE\Mirabilis\
ICQ\DefaultPrefs
HKEY_CURRENT_USER\SOFTWARE\Mirabilis\
ICQ\DefaultPrefs
HKEY_CURRENT_USER\SOFTWARE\RIT\
The Bat!
HKEY_CURRENT_USER\Identities\{341F68BA-C841-4200-A7B4-3D5CFF202166}\
SOFTWARE\Microsoft\Internet Account Manager\
Accounts
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Trillian
HKEY_CURRENT_USER\Software\Far\
Plugins\FTP\Hosts
HKEY_CURRENT_USER\Software\Ghisler\
Windows Commander
HKEY_CURRENT_USER\Software\Ghisler\
Total Commander
HKEY_LOCAL_MACHINE\Software\Ghisler\
Windows Commander
HKEY_LOCAL_MACHINE\Software\Ghisler\
Total Commander
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
&RQ
Dropping Routine
This backdoor drops the following files:
- %User Temp%\~1.exe
- %User Temp%\~2.exe
- %User Temp%\~3.exe
- %User Temp%\~4.exe
- %Windows%\msreg.exe
- %System%\svchostc.exe
- %System%\svchosts.exe
- %Windows%\~2.exe
- %Temp%\temp.dll
- %Windows%\MemChk.exe
(Note: %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.. %Windows% is the Windows folder, which is usually C:\Windows.. %System% is the Windows system folder, which is usually C:\Windows\System32.. %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp.)
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
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\Mirabilis\ICQ
- NewOwners
- In HKEY_LOCAL_MACHINE\SOFTWARE
- Miranda
- In HKEY_LOCAL_MACHINE\SOFTWARE\Mirabilis\ICQ
- DefaultPrefs
- In HKEY_CURRENT_USER\SOFTWARE\Mirabilis\ICQ
- DefaultPrefs
- In HKEY_CURRENT_USER\SOFTWARE\RIT
- The Bat!
- In HKEY_CURRENT_USER\Identities\{341F68BA-C841-4200-A7B4-3D5CFF202166}\SOFTWARE\Microsoft\Internet Account Manager
- Accounts
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall
- Trillian
- In HKEY_CURRENT_USER\Software\Far\Plugins\FTP
- Hosts
- In HKEY_CURRENT_USER\Software\Ghisler
- Windows Commander
- In HKEY_CURRENT_USER\Software\Ghisler
- Total Commander
- In HKEY_LOCAL_MACHINE\Software\Ghisler
- Windows Commander
- In HKEY_LOCAL_MACHINE\Software\Ghisler
- Total Commander
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall
- &RQ
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\Microsoft\Windows\CurrentVersion\Run
- putil = "%Windows%\~2.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- msreg.exe = "%Windows%\msreg.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- Memory Check = "%Windows%\MemChk.exe"
Step 5
Search and delete these components
- %User Temp%\~1.exe
- %User Temp%\~2.exe
- %User Temp%\~3.exe
- %User Temp%\~4.exe
- %Windows%\msreg.exe
- %System%\svchostc.exe
- %System%\svchosts.exe
- %Windows%\~2.exe
- %Temp%\temp.dll
- %Windows%\MemChk.exe
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_BIFROSE.BG. 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 7
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.
- %Temp%\temp.dll
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