WORM_BIFROSE.WDK
Backdoor:Win32/Bifrose.IQ(Microsoft); W32/Autorun.CXP!tr(Fortinet); Win32/Agent.NJO(ESET)
Windows
Threat Type: Worm
Destructiveness: No
Encrypted: Yes
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.
As of this writing, the said sites are inaccessible.
TECHNICAL DETAILS
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 drops the following copies of itself into the affected system and executes them:
- %ProgramData%\CacheMgr.exe (Windows Vista and above)
- %CommonAppData%\CacheMgr.exe (Windows XP and below)
- %System Root%\RECYCLER.xxx\CacheMgr.exe
(Note: %ProgramData% is the Program Data folder, where it usually is C:\Program Files in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData in Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)
It drops the following files:
- %ProgramData%\csetup.tmp (Windows Vista and above)
- %CommonAppData%\csetup.tmp (Windows XP and below)
- %User Temp%\cac{random}.tmp
(Note: %ProgramData% is the Program Data folder, where it usually is C:\Program Files in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData in Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- 2CBE016A-8F28-4E0C-83A6-6079161294D7
- Bif123
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
StubPath = "{file path of dropped copy}" -as
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\2CBE016A-8F28-4E0C-83A6-6079161294D7
StubPath = "{file path of dropped copy}" -ax
It adds the following lines or registry entries as part of its routine:
- HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Tracing\CacheMgr_RASAPI32
- HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Tracing\CacheMgr_RASMANCS
Propagation
This worm drops copies of itself in removable drives. These copies use the names of the following items located on the said drives for their file names:
- Existing folders and appends the extension ".exe"
Download Routine
This worm connects to the following URL(s) to download its component file(s):
- {BLOCKED}es.com/ABIUS/setup.exe
As of this writing, the said sites are inaccessible.
Other Details
This worm connects to the following URL(s) to check for an Internet connection:
- 74.125.224.112
- 74.125.224.113
- 74.125.224.114
- 74.125.224.115
- 74.125.224.116
- 207.46.197.32
- 207.46.232.182
- 129.42.38.1
- 198.133.219.25
NOTES:
The malware drops a copy of itself in the root folders of removable drives using the names of existing folders and appends the extension exe. In addition, the malware changes the attributes of the said folders to HIDDEN making sure that the copies of itself are the one visible with the file names of the folders.
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
Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.
Step 3
Restart in Safe Mode
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\Active Setup\Installed Components
- 2CBE016A-8F28-4E0C-83A6-6079161294D7
- 2CBE016A-8F28-4E0C-83A6-6079161294D7
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- StubPath
- StubPath
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Tracing
- CacheMgr_RASAPI32
- CacheMgr_RASAPI32
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Tracing
- CacheMgr_RASMANCS
- CacheMgr_RASMANCS
Step 5
Search and delete this file
- %ProgramData%\CacheMgr.exe (Windows Vista and above)
- %ProgramData%\csetup.tmp (Windows Vista and above)
- %CommonAppData%\CacheMgr.exe (Windows XP and below)
- %CommonAppData%\csetup.tmp (Windows XP and below)
- %User Temp%\cac{random}.tmp
- %System Root%\RECYCLER.xxx\CacheMgr.exe
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_BIFROSE.WDK. 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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