BKDR_BIFROSE.AFU
Backdoor:Win32/Bifrose (Microsoft); BackDoor-CEP.svr (McAfee); Trojan Horse (Symantec); Trojan.Win32.Agent.bcn, Backdoor.Win32.Bifrose.aci, Backdoor.Win32.Bifrose.adr (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Backdoor:W32/Bifrose.gen!A (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
29,053 bytes
EXE
01 Oct 2011
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%\messengner\msn.exe
(Note: %Windows% is the Windows folder, which is usually C:\Windows.)
It creates the following folders:
- %Windows%\messengner
(Note: %Windows% is the Windows folder, which is usually C:\Windows.)
Other System Modifications
This backdoor deletes the following files:
- %Windows%\messengner\msn.exe
(Note: %Windows% is the Windows folder, which is usually C:\Windows.)
It adds the following registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{A47B24A1-E242-AB90-1800-8EDE1230CFEC}
HKEY_LOCAL_MACHINE\SOFTWARE\Bifrost
HKEY_CURRENT_USER\SOFTWARE\Bifrost
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Control\MediaResources\msvideo
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{A47B24A1-E242-AB90-1800-8EDE1230CFEC}
stubpath = "%Windows%\messengner\msn.exe s"
HKEY_LOCAL_MACHINE\SOFTWARE\Bifrost
nck = {random values}
HKEY_CURRENT_USER\Software\Bifrost
klg = {random values}
This report is generated via an automated analysis system.
SOLUTION
9.200
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components
- {A47B24A1-E242-AB90-1800-8EDE1230CFEC}
- In HKEY_LOCAL_MACHINE\SOFTWARE
- Bifrost
- In HKEY_CURRENT_USER\SOFTWARE
- Bifrost
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\MediaResources
- msvideo
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\SOFTWARE\Microsoft\Active Setup\Installed Components\{A47B24A1-E242-AB90-1800-8EDE1230CFEC}
- stubpath="%Windows%\messengner\msn.exe s"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Bifrost
- nck={random values}
- In HKEY_CURRENT_USER\Software\Bifrost
- klg={random values}
Step 4
Search and delete this folder
Step 5
Scan your computer with your Trend Micro product to delete files detected as BKDR_BIFROSE.AFU. 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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